doc/ref-fdml.xml

   1 <?xml version='1.0' ?>
   2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
   4 <!ENTITY % myents SYSTEM "entities.inc">
   5 %myents;
   6 ]>
   7
   8 <!-- Functional Data Manipulation Language -->
   9 <reference id="ref-fdml">
  10   <title>Functional Data Manipulation Language (FDML)</title>
  11   <partintro>
  12     <para>
  13       The functional data manipulation interface provided by &clsql;
  14       includes functions for inserting, updating and deleting records
  15       in existing database tables and executing SQL queries and
  16       statements with the results of queries returned as Lisp types.
  17       SQL statements expressed as strings may be executed with the
  18       <link linkend="query"><function>query</function></link> and
  19       <link
  20       linkend="execute-command"><function>execute-command</function></link>
  21       functions. The <link
  22       linkend="select"><function>select</function></link> function, on
  23       the other hand, allows for the construction of queries in Lisp
  24       using the symbolic SQL syntax. Finally, iterative manipulation
  25       of query results is supported by <link
  26       linkend="do-query"><function>do-query</function></link>, <link
  27       linkend="map-query"><function>map-query</function></link> and an
  28       extended clause for the <link
  29       linkend="loop-tuples"><function>loop</function></link> macro.
  30     </para>
  31   </partintro>
  32
  33   <!-- Caching table queries -->
  34
  35   <refentry id="cache-table-queries-default">
  36     <refmeta>
  37       <refentrytitle>*CACHE-TABLE-QUERIES-DEFAULT*</refentrytitle>
  38     </refmeta>
  39     <refnamediv>
  40       <refname>*CACHE-TABLE-QUERIES-DEFAULT*</refname>
  41       <refpurpose>Specifies the default behaviour for caching of
  42       attribute types.</refpurpose>
  43       <refclass>Variable</refclass>
  44     </refnamediv>
  45     <refsect1>
  46       <title>Value Type</title>
  47       <para>
  48         A valid argument to the <parameter>action</parameter>
  49         parameter of <function>cache-table-queries</function>,
  50         i.e. one of
  51         <simplelist type="inline">
  52         <member>&t;</member>
  53         <member>&nil;</member>
  54         <member><symbol>:flush</symbol></member>
  55         </simplelist>.
  56       </para>
  57     </refsect1>
  58     <refsect1>
  59       <title>Initial Value</title>
  60       <para><symbol>nil</symbol></para>
  61     </refsect1>
  62     <refsect1>
  63       <title>Description</title>
  64       <para>
  65         Specifies the default behaivour for caching of attribute
  66         types. Meaningful values are &t;, &nil; and
  67         <symbol>:flush</symbol> as described for the
  68         <parameter>action</parameter> argument to
  69         <function>cache-table-queries</function>.
  70       </para>
  71     </refsect1>
  72     <refsect1>
  73       <title>Examples</title>
  74       <para>None.</para>
  75     </refsect1>
  76     <refsect1>
  77       <title>Affected By</title>
  78       <para>None.</para>
  79     </refsect1>
  80     <refsect1>
  81       <title>See Also</title>
  82       <simplelist>
  83         <member><link linkend="cache-table-queries"><function>cache-table-queries</function></link></member>
  84       </simplelist>
  85     </refsect1>
  86     <refsect1>
  87       <title>Notes</title>
  88       <para>None.</para>
  89     </refsect1>
  90   </refentry>
  91
  92   <refentry id="cache-table-queries">
  93     <refmeta>
  94       <refentrytitle>CACHE-TABLE-QUERIES</refentrytitle>
  95     </refmeta>
  96     <refnamediv>
  97       <refname>CACHE-TABLE-QUERIES</refname>
  98       <refpurpose>Control the caching of table attribute types.</refpurpose>
  99       <refclass>Function</refclass>
 100     </refnamediv>
 101     <refsect1>
 102       <title>Syntax</title>
 103       <synopsis>
 104       <function>cache-table-queries</function> <replaceable>table</replaceable> &amp;key <replaceable>action</replaceable> <replaceable>database</replaceable> => <returnvalue></returnvalue></synopsis>
 105     </refsect1>
 106     <refsect1>
 107       <title>Arguments and Values</title>
 108       <variablelist>
 109         <varlistentry>
 110           <term><parameter>table</parameter></term>
 111           <listitem>
 112             <para>
 113               A string representing a database table, &t; or
 114               <symbol>:default</symbol>.
 115             </para>
 116           </listitem>
 117         </varlistentry>
 118         <varlistentry>
 119           <term><parameter>action</parameter></term>
 120           <listitem>
 121             <para>
 122               &t;, &nil; or <symbol>:flush</symbol>.
 123             </para>
 124           </listitem>
 125         </varlistentry>
 126         <varlistentry>
 127           <term><parameter>database</parameter></term>
 128           <listitem>
 129             <para>A
 130             <glossterm linkend="gloss-database-object">database
 131             object</glossterm>. This will default to the value
 132             of <symbol>*default-database*</symbol>.</para>
 133           </listitem>
 134       </varlistentry>
 135       </variablelist>
 136     </refsect1>
 137     <refsect1>
 138       <title>Description</title>
 139       <para>Controls the caching of attribute type information on the
 140       table specified by <parameter>table</parameter> in
 141       <parameter>database</parameter> which defaults to
 142       <symbol>*default-database*</symbol>. <parameter>action</parameter>
 143       specifies the caching behaviour to adopt. If its value is &t;
 144       then attribute type information is cached whereas if its value
 145       is &nil; then attribute type information is not cached. If
 146       <parameter>action</parameter> is <symbol>:flush</symbol> then
 147       all existing type information in the cache for
 148       <parameter>table</parameter> is removed, but caching is still
 149       enabled. <parameter>table</parameter> may be a string
 150       representing a table for which the caching action is to be taken
 151       while the caching action is applied to all tables if
 152       <parameter>table</parameter> is &t;. Alternatively, when
 153       <parameter>table</parameter> is <symbol>:default</symbol>, the
 154       default caching action specified by
 155       <symbol>*cache-table-queries-default*</symbol> is applied to all
 156       tables for which a caching action has not been explicitly set.
 157       </para>
 158     </refsect1>
 159     <refsect1>
 160       <title>Examples</title>
 161       <screen>
 162 (setf *cache-table-queries-default* t)
 163 => T
 164 (create-table [foo]
 165               '(([id] integer)
 166                 ([height] float)
 167                 ([name] (string 24))
 168                 ([comments] varchar)))
 169 =>
 170 (cache-table-queries "foo")
 171 =>
 172 (list-attribute-types "foo")
 173 => (("id" :INT4 4 NIL 1) ("height" :FLOAT8 8 NIL 1) ("name" :BPCHAR 24 NIL 1)
 174     ("comments" :VARCHAR 255 NIL 1))
 175 (drop-table "foo")
 176 =>
 177 (create-table [foo]
 178               '(([id] integer)
 179                 ([height] float)
 180                 ([name] (string 36))
 181                 ([comments] (string 100))))
 182 =>
 183 (cache-table-queries "foo" :action :flush)
 184 =>
 185 (list-attribute-types "foo")
 186 => (("id" :INT4 4 NIL 1) ("height" :FLOAT8 8 NIL 1) ("name" :BPCHAR 36 NIL 1)
 187     ("comments" :BPCHAR 100 NIL 1))
 188       </screen>
 189     </refsect1>
 190     <refsect1>
 191       <title>Side Effects</title>
 192        <para>
 193         The internal attribute cache for
 194         <parameter>database</parameter> is modified.
 195        </para>
 196      </refsect1>
 197     <refsect1>
 198       <title>Affected by</title>
 199       <simplelist>
 200         <member><link linkend="cache-table-queries-default"><symbol>*cache-table-queries-default*</symbol></link></member>
 201       </simplelist>
 202     </refsect1>
 203     <refsect1>
 204       <title>Exceptional Situations</title>
 205       <para>
 206         None.
 207       </para>
 208     </refsect1>
 209     <refsect1>
 210       <title>See Also</title>
 211       <simplelist>
 212         <member><link linkend="cache-table-queries-default"><symbol>*cache-table-queries-default*</symbol></link></member>
 213       </simplelist>
 214     </refsect1>
 215     <refsect1>
 216       <title>Notes</title>
 217       <para>
 218         None.
 219       </para>
 220     </refsect1>
 221   </refentry>
 222
 223   <refentry id="insert-records">
 224     <refmeta>
 225       <refentrytitle>INSERT-RECORDS</refentrytitle>
 226     </refmeta>
 227     <refnamediv>
 228       <refname>INSERT-RECORDS</refname>
 229       <refpurpose>Insert tuples of data into a database table.</refpurpose>
 230       <refclass>Function</refclass>
 231     </refnamediv>
 232     <refsect1>
 233       <title>Syntax</title>
 234       <synopsis>
 235       <function>insert-records</function> &amp;key <replaceable>into</replaceable> <replaceable>attributes</replaceable> <replaceable>values</replaceable> <replaceable>av-pairs</replaceable> <replaceable>query</replaceable> <replaceable>database</replaceable> => <returnvalue></returnvalue></synopsis>
 236     </refsect1>
 237     <refsect1>
 238       <title>Arguments and Values</title>
 239       <variablelist>
 240         <varlistentry>
 241           <term><parameter>into</parameter></term>
 242           <listitem>
 243             <para>
 244               A string, symbol or symbolic SQL expression representing
 245               the name of a table existing in
 246               <parameter>database</parameter>.
 247             </para>
 248           </listitem>
 249         </varlistentry>
 250         <varlistentry>
 251           <term><parameter>attributes</parameter></term>
 252           <listitem>
 253             <para>
 254               A list of attribute identifiers or &nil;.
 255             </para>
 256           </listitem>
 257         </varlistentry>
 258         <varlistentry>
 259           <term><parameter>values</parameter></term>
 260           <listitem>
 261             <para>
 262               A list of attribute values or &nil;.
 263             </para>
 264           </listitem>
 265         </varlistentry>
 266         <varlistentry>
 267           <term><parameter>av-pairs</parameter></term>
 268           <listitem>
 269             <para>
 270               A list of attribute identifier/value pairs or &nil;.
 271             </para>
 272           </listitem>
 273         </varlistentry>
 274         <varlistentry>
 275           <term><parameter>query</parameter></term>
 276           <listitem>
 277             <para>
 278               A query expression or &nil;.
 279             </para>
 280           </listitem>
 281         </varlistentry>
 282         <varlistentry>
 283           <term><parameter>database</parameter></term>
 284           <listitem>
 285             <para>A
 286             <glossterm linkend="gloss-database-object">database
 287             object</glossterm>. This will default to the value
 288             of <symbol>*default-database*</symbol>.</para>
 289           </listitem>
 290       </varlistentry>
 291       </variablelist>
 292     </refsect1>
 293     <refsect1>
 294       <title>Description</title>
 295       <para>
 296         Inserts records into the table specified by
 297         <parameter>into</parameter> in <parameter>database</parameter>
 298         which defaults to <symbol>*default-database*</symbol>.
 299       </para>
 300       <para>
 301         There are five ways of specifying the values inserted into
 302         each row. In the first <parameter>values</parameter> contains
 303         a list of values to insert and
 304         <parameter>attributes</parameter>,
 305         <parameter>av-pairs</parameter> and
 306         <parameter>query</parameter> are &nil;. This can be used when
 307         values are supplied for all attributes in
 308         <parameter>into</parameter>. In the second,
 309         <parameter>attributes</parameter> is a list of column names,
 310         <parameter>values</parameter> is a corresponding list of
 311         values and <parameter>av-pairs</parameter> and
 312         <parameter>query</parameter> are &nil;. In the third,
 313         <parameter>attributes</parameter>,
 314         <parameter>values</parameter> and <parameter>query</parameter>
 315         are &nil; and <parameter>av-pairs</parameter> is an alist of
 316         (attribute value) pairs. In the fourth,
 317         <parameter>values</parameter>, <parameter>av-pairs</parameter>
 318         and <parameter>attributes</parameter> are &nil; and
 319         <parameter>query</parameter> is a symbolic SQL query
 320         expression in which the selected columns also exist in
 321         <parameter>into</parameter>. In the fifth method,
 322         <parameter>values</parameter> and
 323         <parameter>av-pairs</parameter> are nil and
 324         <parameter>attributes</parameter> is a list of column names
 325         and <parameter>query</parameter> is a symbolic SQL query
 326         expression which returns values for the specified columns.
 327       </para>
 328     </refsect1>
 329     <refsect1>
 330       <title>Examples</title>
 331       <screen>
 332 (select [first-name] [last-name] [email]
 333         :from [employee]
 334         :where [= [emplid] 11]
 335         :field-names nil)
 336 => NIL
 337 (insert-records :into [employee]
 338                 :attributes '(emplid groupid first_name last_name email
 339                               ecompanyid managerid)
 340                 :values '(11 1 "Yuri" "Gagarin" "gagarin@soviet.org"
 341                           1 1))
 342 =>
 343 (select [first-name] [last-name] [email]
 344         :from [employee]
 345         :where [= [emplid] 11]
 346         :field-names nil)
 347 => (("Yuri" "Gagarin" "gagarin@soviet.org"))
 348       </screen>
 349     </refsect1>
 350     <refsect1>
 351       <title>Side Effects</title>
 352       <para>
 353         Modifications are made to the underlying database.
 354       </para>
 355     </refsect1>
 356     <refsect1>
 357       <title>Affected by</title>
 358       <para>
 359         None.
 360       </para>
 361     </refsect1>
 362     <refsect1>
 363       <title>Exceptional Situations</title>
 364       <para>
 365         An error of type <symbol>sql-database-data-error</symbol> is
 366         signalled if <parameter>table</parameter> is not an existing
 367         table in <parameter>database</parameter> or if the specified
 368         attributes are not found.
 369       </para>
 370     </refsect1>
 371     <refsect1>
 372       <title>See Also</title>
 373       <simplelist>
 374         <member><link linkend="update-records"><function>update-records</function></link></member>
 375         <member><link linkend="delete-records"><function>delete-records</function></link></member>
 376       </simplelist>
 377     </refsect1>
 378     <refsect1>
 379       <title>Notes</title>
 380       <para>
 381         None.
 382       </para>
 383     </refsect1>
 384   </refentry>
 385
 386   <refentry id="update-records">
 387     <refmeta>
 388       <refentrytitle>UPDATE-RECORDS</refentrytitle>
 389     </refmeta>
 390     <refnamediv>
 391       <refname>UPDATE-RECORDS</refname>
 392       <refpurpose>Updates the values of existing records.</refpurpose>
 393       <refclass>Function</refclass>
 394     </refnamediv>
 395     <refsect1>
 396       <title>Syntax</title>
 397       <synopsis>
 398       <function>update-records</function> <replaceable>table</replaceable> &amp;key  <replaceable>attributes</replaceable> <replaceable>values</replaceable> <replaceable>av-pairs</replaceable> <replaceable>where</replaceable> <replaceable>database</replaceable> => <returnvalue></returnvalue></synopsis>
 399     </refsect1>
 400     <refsect1>
 401       <title>Arguments and Values</title>
 402       <variablelist>
 403         <varlistentry>
 404           <term><parameter>table</parameter></term>
 405           <listitem>
 406             <para>
 407               A string, symbol or symbolic SQL expression representing
 408               the name of a table existing in
 409               <parameter>database</parameter>.
 410             </para>
 411           </listitem>
 412         </varlistentry>
 413         <varlistentry>
 414           <term><parameter>attributes</parameter></term>
 415           <listitem>
 416             <para>
 417               A list of attribute identifiers or &nil;.
 418             </para>
 419           </listitem>
 420         </varlistentry>
 421         <varlistentry>
 422           <term><parameter>values</parameter></term>
 423           <listitem>
 424             <para>
 425               A list of attribute values or &nil;.
 426             </para>
 427           </listitem>
 428         </varlistentry>
 429         <varlistentry>
 430           <term><parameter>av-pairs</parameter></term>
 431           <listitem>
 432             <para>
 433               A list of attribute identifier/value pairs or &nil;.
 434             </para>
 435           </listitem>
 436         </varlistentry>
 437         <varlistentry>
 438           <term><parameter>where</parameter></term>
 439           <listitem>
 440             <para>
 441               A symbolic SQL expression.
 442             </para>
 443           </listitem>
 444         </varlistentry>
 445         <varlistentry>
 446           <term><parameter>database</parameter></term>
 447           <listitem>
 448             <para>A
 449             <glossterm linkend="gloss-database-object">database
 450             object</glossterm>. This will default to the value
 451             of <symbol>*default-database*</symbol>.</para>
 452           </listitem>
 453       </varlistentry>
 454       </variablelist>
 455     </refsect1>
 456     <refsect1>
 457       <title>Description</title>
 458       <para>
 459         Updates the attribute values of existing records satsifying
 460         the SQL expression <parameter>where</parameter> in the table
 461         specified by <parameter>table</parameter> in
 462         <parameter>database</parameter> which defaults to
 463         <symbol>*default-database*</symbol>.
 464       </para>
 465       <para>
 466         There are three ways of specifying the values to update for
 467         each row. In the first, <parameter>values</parameter> contains
 468         a list of values to use in the update and
 469         <parameter>attributes</parameter> and
 470         <parameter>av-pairs</parameter> are &nil;. This can be used
 471         when values are supplied for all attributes in
 472         <parameter>table</parameter>. In the second,
 473         <parameter>attributes</parameter> is a list of column names,
 474         <parameter>values</parameter> is a corresponding list of
 475         values and <parameter>av-pairs</parameter> is &nil;. In the
 476         third, <parameter>attributes</parameter> and
 477         <parameter>values</parameter> are &nil; and
 478         <parameter>av-pairs</parameter> is an alist of (attribute
 479         value) pairs.
 480       </para>
 481     </refsect1>
 482     <refsect1>
 483       <title>Examples</title>
 484       <screen>
 485 (select [first-name] [last-name] [email]
 486         :from [employee]
 487         :where [= [emplid] 1]
 488         :field-names nil)
 489 => (("Vladimir" "Lenin" "lenin@soviet.org"))
 490 (update-records [employee]
 491                 :av-pairs'((first_name "Yuri")
 492                            (last_name "Gagarin")
 493                            (email "gagarin@soviet.org"))
 494                 :where [= [emplid] 1])
 495 =>
 496 (select [first-name] [last-name] [email]
 497         :from [employee]
 498         :where [= [emplid] 1]
 499         :field-names nil)
 500 => (("Yuri" "Gagarin" "gagarin@soviet.org"))
 501       </screen>
 502     </refsect1>
 503     <refsect1>
 504       <title>Side Effects</title>
 505       <para>
 506         Modifications are made to the underlying database.
 507       </para>
 508     </refsect1>
 509     <refsect1>
 510       <title>Affected by</title>
 511       <para>
 512         None.
 513       </para>
 514     </refsect1>
 515     <refsect1>
 516       <title>Exceptional Situations</title>
 517       <para>
 518         An error of type <symbol>sql-database-data-error</symbol> is
 519         signalled if <parameter>table</parameter> is not an existing
 520         table in <parameter>database</parameter>, if the specified
 521         attributes are not found or if the SQL statement resulting
 522         from the symbolic expression <parameter>where</parameter> does
 523         not return a Boolean value.
 524       </para>
 525       <para>If the execution of the SQL query leads to any errors, an
 526       error of type <errortype>sql-database-error</errortype> is
 527       signalled.</para>
 528     </refsect1>
 529     <refsect1>
 530       <title>See Also</title>
 531       <para>
 532         <simplelist>
 533           <member><link linkend="insert-records"><function>insert-records</function></link></member>
 534           <member><link linkend="delete-records"><function>delete-records</function></link></member>
 535         </simplelist>
 536       </para>
 537     </refsect1>
 538     <refsect1>
 539       <title>Notes</title>
 540       <para>
 541         None.
 542       </para>
 543     </refsect1>
 544   </refentry>
 545
 546   <refentry id="delete-records">
 547     <refmeta>
 548       <refentrytitle>DELETE-RECORDS</refentrytitle>
 549     </refmeta>
 550     <refnamediv>
 551       <refname>DELETE-RECORDS</refname>
 552       <refpurpose>Delete records from a database table.</refpurpose>
 553       <refclass>Function</refclass>
 554     </refnamediv>
 555     <refsect1>
 556       <title>Syntax</title>
 557       <synopsis>
 558       <function>delete-records</function> &amp;key <replaceable>from</replaceable> <replaceable>where</replaceable> <replaceable>database</replaceable> => <returnvalue></returnvalue></synopsis>
 559     </refsect1>
 560     <refsect1>
 561       <title>Arguments and Values</title>
 562       <variablelist>
 563         <varlistentry>
 564           <term><parameter>from</parameter></term>
 565           <listitem>
 566             <para>
 567               A string, symbol or symbolic SQL expression representing
 568               the name of a table existing in
 569               <parameter>database</parameter>.
 570             </para>
 571           </listitem>
 572         </varlistentry>
 573                 <varlistentry>
 574           <term><parameter>where</parameter></term>
 575           <listitem>
 576             <para>
 577               A symbolic SQL expression.
 578             </para>
 579           </listitem>
 580         </varlistentry>
 581         <varlistentry>
 582           <term><parameter>database</parameter></term>
 583           <listitem>
 584             <para>A
 585             <glossterm linkend="gloss-database-object">database
 586             object</glossterm>. This will default to the value
 587             of <symbol>*default-database*</symbol>.</para>
 588           </listitem>
 589         </varlistentry>
 590       </variablelist>
 591     </refsect1>
 592     <refsect1>
 593       <title>Description</title>
 594       <para>Deletes records satisfying the SQL expression
 595       <parameter>where</parameter> from the table specified by
 596       <parameter>from</parameter> in <parameter>database</parameter>
 597       specifies a database which defaults to
 598       <symbol>*default-database*</symbol>.
 599       </para>
 600     </refsect1>
 601     <refsect1>
 602       <title>Examples</title>
 603       <screen>
 604 (select [first-name] [last-name] [email]
 605         :from [employee]
 606         :where [= [emplid] 11]
 607         :field-names nil)
 608 => (("Yuri" "Gagarin" "gagarin@soviet.org"))
 609 (delete-records :from [employee] :where [= [emplid] 11])
 610 =>
 611 (select [first-name] [last-name] [email]
 612         :from [employee]
 613         :where [= [emplid] 11]
 614         :field-names nil)
 615 => NIL
 616       </screen>
 617     </refsect1>
 618     <refsect1>
 619       <title>Side Effects</title>
 620       <para>
 621         Modifications are made to the underlying database.
 622       </para>
 623     </refsect1>
 624     <refsect1>
 625       <title>Affected by</title>
 626       <para>
 627         None.
 628       </para>
 629     </refsect1>
 630     <refsect1>
 631       <title>Exceptional Situations</title>
 632       <para>
 633         An error of type <symbol>sql-database-data-error</symbol> is
 634         signalled if <parameter>from</parameter> is not an existing
 635         table in <parameter>database</parameter> or if the SQL
 636         statement resulting from the symbolic expression
 637         <parameter>where</parameter> does not return a Boolean value.
 638       </para>
 639     </refsect1>
 640     <refsect1>
 641       <title>See Also</title>
 642       <para>
 643         <simplelist>
 644           <member><link linkend="insert-records"><function>insert-records</function></link></member>
 645           <member><link linkend="update-records"><function>update-records</function></link></member>
 646         </simplelist>
 647       </para>
 648     </refsect1>
 649     <refsect1>
 650       <title>Notes</title>
 651       <para>
 652         None.
 653       </para>
 654     </refsect1>
 655   </refentry>
 656
 657
 658   <!-- executing SQL commands and queries -->
 659
 660   <refentry id="execute-command">
 661     <refmeta>
 662       <refentrytitle>EXECUTE-COMMAND</refentrytitle>
 663     </refmeta>
 664     <refnamediv>
 665       <refname>EXECUTE-COMMAND</refname>
 666       <refpurpose>Execute an SQL command which returns no values.</refpurpose>
 667       <refclass>Generic Function</refclass>
 668     </refnamediv>
 669     <refsect1>
 670       <title>Syntax</title>
 671       <synopsis>
 672       <function>execute-command</function> <replaceable>sql-expression</replaceable> &amp;key <replaceable>database</replaceable> => <returnvalue></returnvalue></synopsis>
 673     </refsect1>
 674     <refsect1>
 675       <title>Arguments and Values</title>
 676       <variablelist>
 677         <varlistentry>
 678           <term><parameter>sql-expression</parameter></term>
 679           <listitem>
 680             <para>An <glossterm linkend="gloss-sql-expression">sql
 681             expression</glossterm> that represents an SQL
 682             statement which will return no values.</para>
 683           </listitem>
 684         </varlistentry>
 685         <varlistentry>
 686           <term><parameter>database</parameter></term>
 687           <listitem>
 688             <para>A
 689             <glossterm linkend="gloss-database-object">database
 690             object</glossterm>. This will default to the value
 691             of <symbol>*default-database*</symbol>.</para>
 692           </listitem>
 693       </varlistentry></variablelist>
 694     </refsect1>
 695     <refsect1>
 696       <title>Description</title>
 697       <para>Executes the SQL command
 698       <parameter>sql-expression</parameter>, which may be a symbolic
 699       SQL expression or a string representing any SQL statement apart
 700       from a query, on the supplied <parameter>database</parameter>
 701       which defaults to <symbol>*default-database*</symbol>.
 702       </para>
 703     </refsect1>
 704     <refsect1>
 705       <title>Examples</title>
 706       <screen>
 707         (execute-command "create table eventlog (time char(30),event char(70))")
 708         =>
 709
 710         (execute-command "create table eventlog (time char(30),event char(70))")
 711         >>
 712         >> While accessing database #&lt;CLSQL-POSTGRESQL:POSTGRESQL-DATABASE {480B2B6D}>
 713         >>   with expression "create table eventlog (time char(30),event char(70))":
 714         >>   Error NIL: ERROR:  amcreate: eventlog relation already exists
 715         >>   has occurred.
 716         >>
 717         >> Restarts:
 718         >>   0: [ABORT] Return to Top-Level.
 719         >>
 720         >> Debug  (type H for help)
 721         >>
 722         >> (CLSQL-POSTGRESQL::|(PCL::FAST-METHOD DATABASE-EXECUTE-COMMAND (T POSTGRESQL-DATABASE))|
 723         >>  #&lt;unused-arg>
 724         >>  #&lt;unused-arg>
 725         >>  #&lt;unavailable-arg>
 726         >>  #&lt;unavailable-arg>)
 727         >> Source: (ERROR 'SQL-DATABASE-ERROR :DATABASE DATABASE :EXPRESSION ...)
 728         >> 0] 0
 729
 730         (execute-command "drop table eventlog")
 731         =>
 732       </screen>
 733     </refsect1>
 734     <refsect1>
 735       <title>Side Effects</title>
 736       <para>Whatever effects the execution of the SQL statement has
 737       on the underlying database, if any.</para>
 738     </refsect1>
 739     <refsect1>
 740       <title>Affected by</title>
 741       <para>None.</para>
 742     </refsect1>
 743     <refsect1>
 744       <title>Exceptional Situations</title>
 745       <para>If the execution of the SQL statement leads to any errors,
 746       an error of type <errortype>sql-database-error</errortype> is
 747       signalled.</para>
 748     </refsect1>
 749     <refsect1>
 750       <title>See Also</title>
 751       <para>
 752         <simplelist>
 753           <member><link linkend="query"><function>query</function></link></member>
 754         </simplelist>
 755       </para>
 756     </refsect1>
 757     <refsect1>
 758       <title>Notes</title>
 759       <para>None.</para>
 760     </refsect1>
 761   </refentry>
 762
 763
 764   <refentry id="query">
 765     <refmeta>
 766       <refentrytitle>QUERY</refentrytitle>
 767     </refmeta>
 768     <refnamediv>
 769       <refname>QUERY</refname>
 770       <refpurpose>Execute an SQL query and return the tuples as a
 771       list.</refpurpose>
 772       <refclass>Generic Function</refclass>
 773     </refnamediv>
 774     <refsect1>
 775       <title>Syntax</title>
 776       <synopsis>
 777       <function>query</function> <replaceable>query-expression</replaceable> &amp;key <replaceable>database</replaceable> <replaceable>result-types</replaceable> <replaceable>flatp</replaceable> <replaceable>field-names</replaceable> => <returnvalue>result</returnvalue></synopsis>
 778     </refsect1>
 779     <refsect1>
 780       <title>Arguments and Values</title>
 781       <variablelist>
 782         <varlistentry>
 783           <term><parameter>query-expression</parameter></term>
 784           <listitem>
 785             <para>An <glossterm linkend="gloss-sql-expression">sql
 786             expression</glossterm> that represents an SQL
 787             query which is expected to return a (possibly empty)
 788             result set.</para>
 789           </listitem>
 790         </varlistentry>
 791         <varlistentry>
 792           <term><parameter>database</parameter></term>
 793           <listitem>
 794             <para>A
 795             <glossterm linkend="gloss-database-object">database
 796             object</glossterm>. This will default to the value
 797             of <symbol>*default-database*</symbol>.</para>
 798           </listitem>
 799         </varlistentry>
 800         <varlistentry>
 801           <term><parameter>flatp</parameter></term>
 802           <listitem>
 803             <para>A Boolean whose default value is &nil;.</para>
 804           </listitem>
 805         </varlistentry>
 806         <varlistentry>
 807           <term><parameter>result-types</parameter></term>
 808           <listitem>
 809             <para>A
 810             <glossterm linkend="gloss-field-types">field type
 811             specifier</glossterm>. The default is &nil;.
 812             </para>
 813             <para>
 814               The purpose of this argument is cause &clsql; to
 815               import SQL numeric fields into numeric Lisp objects
 816               rather than strings. This reduces the cost of
 817               allocating a temporary string and the &clsql; users'
 818               inconvenience of converting number strings into number
 819               objects.
 820             </para>
 821             <para>
 822               A value of <symbol>:auto</symbol> causes &clsql;
 823               to automatically convert SQL fields into a
 824               numeric format where applicable. The default value of
 825               &nil; causes all fields to be returned as strings
 826               regardless of the SQL type. Otherwise a list is expected
 827               which has a element for each field that specifies the
 828               conversion. Valid type identifiers are:
 829               <simplelist type="vert">
 830                 <member><symbol>:int</symbol> Field is imported as a
 831                 signed integer, from 8-bits to 64-bits depending
 832                 upon the field type.
 833                 </member>
 834                 <member><symbol>:double</symbol> Field is imported as a
 835                 double-float number.
 836                 </member>
 837                 <member><symbol>t</symbol> Field is imported as a
 838                 string.
 839                 </member>
 840               </simplelist>
 841               If the list is shorter than the number of fields, the a
 842               value of <symbol>t</symbol> is assumed for the field.
 843               If the list is longer than the number of fields, the
 844               extra elements are ignored.
 845             </para>
 846           </listitem>
 847         </varlistentry>
 848         <varlistentry>
 849           <term><parameter>field-names</parameter></term>
 850           <listitem>
 851           <para>
 852             A boolean with a default value of &t;. When &t;, this
 853             function returns a second value of a list of field
 854             names. When &nil;, this function only returns one value -
 855             the list of rows.
 856           </para>
 857           </listitem>
 858         </varlistentry>
 859         <varlistentry>
 860           <term><returnvalue>result</returnvalue></term>
 861           <listitem>
 862             <para>A list representing the result set obtained.  For
 863             each tuple in the result set, there is an element in
 864             this list, which is itself a list of all the attribute
 865             values in the tuple.</para>
 866           </listitem>
 867         </varlistentry>
 868       </variablelist>
 869     </refsect1>
 870     <refsect1>
 871       <title>Description</title>
 872       <para>
 873         Executes the SQL query expression
 874         <parameter>query-expression</parameter>, which may be an SQL
 875         expression or a string, on the supplied
 876         <parameter>database</parameter> which defaults to
 877         <symbol>*default-database*</symbol>. <parameter>result-types</parameter>
 878         is a list of symbols which specifies the lisp type for each
 879         field returned by <parameter>query-expression</parameter>.
 880       </para>
 881       <para>
 882         If <parameter>result-types</parameter> is &nil; all results
 883         are returned as strings whereas the default value of
 884         <symbol>:auto</symbol> means that the lisp types are
 885         automatically computed for each field.
 886       </para>
 887       <para>
 888         <parameter>field-names</parameter> is &t; by default which
 889         means that the second value returned is a list of strings
 890         representing the columns selected by
 891         <parameter>query-expression</parameter>. If
 892         <parameter>field-names</parameter> is &nil;, the list of column
 893         names is not returned as a second value.
 894       </para>
 895       <para>
 896         <parameter>flatp</parameter> has a default value of &nil;
 897         which means that the results are returned as a list of
 898         lists.If FLATP is &t; and only one result is returned for each
 899         record selected by <parameter>query-expression</parameter>,
 900         the results are returned as elements of a list.
 901       </para>
 902     </refsect1>
 903     <refsect1>
 904       <title>Examples</title>
 905       <screen>
 906 (query "select emplid,first_name,last_name,height from employee where emplid = 1")
 907 => ((1 "Vladimir" "Lenin" 1.5564661d0)),
 908    ("emplid" "first_name" "last_name" "height")
 909
 910 (query "select emplid,first_name,last_name,height from employee where emplid = 1"
 911        :field-names nil)
 912 => ((1 "Vladimir" "Lenin" 1.5564661d0))
 913
 914 (query "select emplid,first_name,last_name,height from employee where emplid = 1"
 915        :field-names nil
 916        :result-types nil)
 917 => (("1" "Vladimir" "Lenin" "1.5564661"))
 918
 919 (query "select emplid,first_name,last_name,height from employee where emplid = 1"
 920        :field-names nil
 921        :result-types '(:int t t :double))
 922 => ((1 "Vladimir" "Lenin" 1.5564661))
 923
 924 (query "select last_name from employee where emplid > 5" :flatp t)
 925 => ("Andropov" "Chernenko" "Gorbachev" "Yeltsin" "Putin"),
 926    ("last_name")
 927
 928 (query "select last_name from employee where emplid > 10"
 929        :flatp t
 930        :field-names nil)
 931 => NIL
 932       </screen>
 933     </refsect1>
 934     <refsect1>
 935       <title>Side Effects</title>
 936       <para>Whatever effects the execution of the SQL query has
 937       on the underlying database, if any.</para>
 938     </refsect1>
 939     <refsect1>
 940       <title>Affected by</title>
 941       <para>None.</para>
 942     </refsect1>
 943     <refsect1>
 944       <title>Exceptional Situations</title>
 945       <para>If the execution of the SQL query leads to any errors, an
 946       error of type <errortype>sql-database-error</errortype> is
 947       signalled.</para>
 948     </refsect1>
 949     <refsect1>
 950       <title>See Also</title>
 951       <simplelist>
 952         <member><link linkend="execute-command"><function>execute-command</function></link></member>
 953         <member><link linkend="print-query"><function>print-query</function></link></member>
 954         <member><link linkend="do-query"><function>do-query</function></link></member>
 955         <member><link linkend="map-query"><function>map-query</function></link></member>
 956         <member><link linkend="loop-tuples"><function>loop</function></link></member>
 957         <member><link linkend="select"><function>select</function></link></member>
 958       </simplelist>
 959     </refsect1>
 960     <refsect1>
 961       <title>Notes</title>
 962       <para>The <parameter>field-names</parameter> and
 963       <parameter>result-types</parameter> keyword arguments are a
 964       &clsql; extension.</para>
 965     </refsect1>
 966   </refentry>
 967
 968   <refentry id="print-query">
 969     <refmeta>
 970       <refentrytitle>PRINT-QUERY</refentrytitle>
 971     </refmeta>
 972     <refnamediv>
 973       <refname>PRINT-QUERY</refname>
 974       <refpurpose>Prints a tabular report of query results.</refpurpose>
 975       <refclass>Function</refclass>
 976     </refnamediv>
 977     <refsect1>
 978       <title>Syntax</title>
 979       <synopsis>
 980       <function>print-query</function> <replaceable>query-expression</replaceable> &amp;key <replaceable>titles</replaceable> <replaceable>formats</replaceable> <replaceable>sizes</replaceable> <replaceable>stream</replaceable> <replaceable>database</replaceable> => <returnvalue></returnvalue></synopsis>
 981     </refsect1>
 982     <refsect1>
 983       <title>Arguments and Values</title>
 984       <variablelist>
 985         <varlistentry>
 986           <term><parameter>query-expression</parameter></term>
 987           <listitem>
 988             <para>An <glossterm linkend="gloss-sql-expression">sql
 989             expression</glossterm> that represents an SQL
 990             query which is expected to return a (possibly empty)
 991             result set.</para>
 992           </listitem>
 993         </varlistentry>
 994         <varlistentry>
 995           <term><parameter>database</parameter></term>
 996           <listitem>
 997             <para>A
 998             <glossterm linkend="gloss-database-object">database
 999             object</glossterm>. This will default to the value
1000             of <symbol>*default-database*</symbol>.</para>
1001           </listitem>
1002         </varlistentry>
1003         <varlistentry>
1004           <term><parameter>titles</parameter></term>
1005           <listitem>
1006             <para>
1007               A list of strings or &nil; which is the default value.
1008             </para>
1009           </listitem>
1010         </varlistentry>
1011         <varlistentry>
1012           <term><parameter>formats</parameter></term>
1013           <listitem>
1014             <para>
1015               A list of strings, &nil; or &t; which is the default value.
1016             </para>
1017           </listitem>
1018         </varlistentry>
1019         <varlistentry>
1020           <term><parameter>sizes</parameter></term>
1021           <listitem>
1022             <para>
1023               A list of numbers, &nil; or &t; which is the default value.
1024             </para>
1025           </listitem>
1026         </varlistentry>
1027         <varlistentry>
1028           <term><parameter>stream</parameter></term>
1029           <listitem>
1030             <para>
1031               An output stream or &t; which is the default value.
1032             </para>
1033           </listitem>
1034         </varlistentry>
1035       </variablelist>
1036     </refsect1>
1037     <refsect1>
1038       <title>Description</title>
1039       <para>Prints a tabular report of the results returned by the SQL
1040       query <parameter>query-expression</parameter>, which may be a
1041       symbolic SQL expression or a string, in
1042       <parameter>database</parameter> which defaults to
1043       <symbol>*default-database*</symbol>. The report is printed onto
1044       <parameter>stream</parameter> which has a default value of &t;
1045       which means that <symbol>*standard-output*</symbol> is used. The
1046       <parameter>title</parameter> argument, which defaults to &nil;,
1047       allows the specification of a list of strings to use as column
1048       titles in the tabular output. <parameter>sizes</parameter>
1049       accepts a list of column sizes, one for each column selected by
1050       <parameter>query-expression</parameter>, to use in formatting
1051       the tabular report. The default value of &t; means that minimum
1052       sizes are computed. <parameter>formats</parameter> is a list of
1053       format strings to be used for printing each column selected by
1054       <parameter>query-expression</parameter>. The default value of
1055       <parameter>formats</parameter> is &t; meaning that
1056       <symbol>~A</symbol> is used to format all columns or
1057       <symbol>~VA</symbol> if column sizes are used.
1058       </para>
1059     </refsect1>
1060     <refsect1>
1061       <title>Examples</title>
1062       <screen>
1063 (print-query [select [emplid] [first-name] [last-name] [email]
1064                      :from [employee]
1065                      :where [&lt; [emplid] 5]]
1066               :titles '("ID" "FORENAME" "SURNAME" "EMAIL"))
1067 ID FORENAME SURNAME  EMAIL
1068 1  Vladimir Lenin    lenin@soviet.org
1069 2  Josef    Stalin   stalin@soviet.org
1070 3  Leon     Trotsky  trotsky@soviet.org
1071 4  Nikita   Kruschev kruschev@soviet.org
1072 =>
1073
1074 (print-query "select emplid,first_name,last_name,email from employee where emplid >= 5"
1075              :titles '("ID" "FORENAME" "SURNAME" "EMAIL"))
1076 ID FORENAME   SURNAME   EMAIL
1077 5  Leonid     Brezhnev  brezhnev@soviet.org
1078 6  Yuri       Andropov  andropov@soviet.org
1079 7  Konstantin Chernenko chernenko@soviet.org
1080 8  Mikhail    Gorbachev gorbachev@soviet.org
1081 9  Boris      Yeltsin   yeltsin@soviet.org
1082 10 Vladimir   Putin     putin@soviet.org
1083 =>
1084 </screen>
1085     </refsect1>
1086     <refsect1>
1087       <title>Side Effects</title>
1088       <para>
1089         None.
1090       </para>
1091     </refsect1>
1092     <refsect1>
1093       <title>Affected by</title>
1094       <para>
1095         None.
1096       </para>
1097     </refsect1>
1098     <refsect1>
1099       <title>Exceptional Situations</title>
1100       <para>
1101         If the execution of the SQL query leads to any errors, an
1102         error of type <errortype>sql-database-error</errortype> is
1103         signalled.
1104       </para>
1105     </refsect1>
1106     <refsect1>
1107       <title>See Also</title>
1108       <simplelist>
1109         <member><link linkend="query"><function>query</function></link></member>
1110         <member><link linkend="do-query"><function>do-query</function></link></member>
1111         <member><link linkend="map-query"><function>map-query</function></link></member>
1112         <member><link linkend="loop-tuples"><function>loop</function></link></member>
1113         <member><link linkend="select"><function>select</function></link></member>
1114       </simplelist>
1115     </refsect1>
1116     <refsect1>
1117       <title>Notes</title>
1118       <para>
1119         None.
1120       </para>
1121     </refsect1>
1122   </refentry>
1123
1124   <refentry id="select">
1125     <refmeta>
1126       <refentrytitle>SELECT</refentrytitle>
1127     </refmeta>
1128     <refnamediv>
1129       <refname>SELECT</refname>
1130       <refpurpose>Executes a query given the supplied constraints.</refpurpose>
1131       <refclass>Function</refclass>
1132     </refnamediv>
1133     <refsect1>
1134       <title>Syntax</title>
1135       <synopsis>
1136       <function>select</function> &amp;rest <replaceable>identifiers</replaceable> &amp;key <replaceable>all</replaceable> <replaceable>distinct</replaceable> <replaceable>from</replaceable> <replaceable>group-by</replaceable> <replaceable>having</replaceable> <replaceable>order-by</replaceable> <replaceable>set-operation</replaceable> <replaceable>where</replaceable> <replaceable>result-types</replaceable> <replaceable>field-names</replaceable> <replaceable>flatp</replaceable> <replaceable>refresh</replaceable> <replaceable>caching</replaceable> <replaceable>database</replaceable> => <returnvalue>result</returnvalue></synopsis>
1137     </refsect1>
1138     <refsect1>
1139       <title>Arguments and Values</title>
1140       <variablelist>
1141         <varlistentry>
1142           <term><parameter>identifiers</parameter></term>
1143           <listitem>
1144             <para>
1145               A set of <glossterm linkend="gloss-sql-expression">sql
1146               expressions</glossterm> each of which indicates a column
1147               to query.
1148             </para>
1149           </listitem>
1150         </varlistentry>
1151         <varlistentry>
1152           <term><parameter>all</parameter></term>
1153           <listitem>
1154             <para>
1155               A Boolean.
1156             </para>
1157           </listitem>
1158         </varlistentry>
1159         <varlistentry>
1160           <term><parameter>distinct</parameter></term>
1161           <listitem>
1162             <para>
1163               A Boolean.
1164             </para>
1165           </listitem>
1166         </varlistentry>
1167         <varlistentry>
1168           <term><parameter>from</parameter></term>
1169           <listitem>
1170             <para>
1171               One or more SQL expression representing tables.
1172             </para>
1173           </listitem>
1174         </varlistentry>
1175         <varlistentry>
1176           <term><parameter>group-by</parameter></term>
1177           <listitem>
1178             <para>
1179               An SQL expression.
1180             </para>
1181           </listitem>
1182         </varlistentry>
1183         <varlistentry>
1184           <term><parameter>having</parameter></term>
1185           <listitem>
1186             <para>
1187               An SQL expression.
1188             </para>
1189           </listitem>
1190         </varlistentry>
1191         <varlistentry>
1192           <term><parameter>order-by</parameter></term>
1193           <listitem>
1194             <para>
1195               An SQL expression.
1196             </para>
1197           </listitem>
1198         </varlistentry>
1199         <varlistentry>
1200           <term><parameter>set-operation</parameter></term>
1201           <listitem>
1202             <para>
1203               An SQL expression.
1204             </para>
1205           </listitem>
1206         </varlistentry>
1207         <varlistentry>
1208           <term><parameter>where</parameter></term>
1209           <listitem>
1210             <para>
1211               An SQL expression.
1212             </para>
1213           </listitem>
1214         </varlistentry>
1215         <varlistentry>
1216           <term><parameter>database</parameter></term>
1217           <listitem>
1218             <para>A
1219             <glossterm linkend="gloss-database-object">database
1220             object</glossterm>. This will default to the value
1221             of <symbol>*default-database*</symbol>.</para>
1222           </listitem>
1223         </varlistentry>
1224         <varlistentry>
1225           <term><parameter>flatp</parameter></term>
1226           <listitem>
1227             <para>A Boolean whose default value is &nil;.</para>
1228           </listitem>
1229         </varlistentry>
1230         <varlistentry>
1231           <term><parameter>result-types</parameter></term>
1232           <listitem>
1233             <para>A
1234             <glossterm linkend="gloss-field-types">field type
1235             specifier</glossterm>. The default is &nil;.
1236             </para>
1237             <para>
1238               The purpose of this argument is cause &clsql; to
1239               import SQL numeric fields into numeric Lisp objects
1240               rather than strings. This reduces the cost of
1241               allocating a temporary string and the &clsql; users'
1242               inconvenience of converting number strings into number
1243               objects.
1244             </para>
1245             <para>
1246               A value of <symbol>:auto</symbol> causes &clsql;
1247               to automatically convert SQL fields into a
1248               numeric format where applicable. The default value of
1249               &nil; causes all fields to be returned as strings
1250               regardless of the SQL type. Otherwise a list is expected
1251               which has a element for each field that specifies the
1252               conversion. Valid type identifiers are:
1253               <simplelist type="vert">
1254                 <member><symbol>:int</symbol> Field is imported as a
1255                 signed integer, from 8-bits to 64-bits depending
1256                 upon the field type.
1257                 </member>
1258                 <member><symbol>:double</symbol> Field is imported as a
1259                 double-float number.
1260                 </member>
1261                 <member><symbol>t</symbol> Field is imported as a
1262                 string.
1263                 </member>
1264               </simplelist>
1265               If the list is shorter than the number of fields, the a
1266               value of <symbol>t</symbol> is assumed for the field.
1267               If the list is longer than the number of fields, the
1268               extra elements are ignored.
1269             </para>
1270           </listitem>
1271         </varlistentry>
1272         <varlistentry>
1273           <term><parameter>field-names</parameter></term>
1274           <listitem>
1275           <para>
1276             A boolean with a default value of &t;. When &t;, this
1277             function returns a second value of a list of field
1278             names. When &nil;, this function only returns one value -
1279             the list of rows.
1280           </para>
1281           </listitem>
1282         </varlistentry>
1283         <varlistentry>
1284           <term><parameter>refresh</parameter></term>
1285           <listitem>
1286           <para>
1287             This value is only considered when CLOS objects are being
1288             selected. A boolean with a default value of &nil;. When
1289             the value of the <varname>caching</varname> keyword is
1290             &t;, a second equivalent <function>select</function> call
1291             will return the same view class instance objects. When
1292             <varname>refresh</varname> is &t;, then slots of the
1293             existing instances are updated as necessary. In such
1294             cases, you may wish to override the hook
1295             <function>instance-refresh</function>.
1296           </para>
1297           </listitem>
1298         </varlistentry>
1299         <varlistentry>
1300           <term><parameter>caching</parameter></term>
1301           <listitem>
1302           <para>
1303             This value is only considered when CLOS objects are being
1304             selected.  A boolean with a default value of
1305             <varname>*default-caching*</varname>. &clsql; caches
1306             objects in accordance with the &commonsql; interface: a
1307             second equivalent <function>select</function> call will
1308             return the same view class instance objects.
1309           </para>
1310           </listitem>
1311         </varlistentry>
1312         <varlistentry>
1313           <term><parameter>result</parameter></term>
1314           <listitem>
1315             <para>
1316               A list representing the result set obtained.  For each
1317               tuple in the result set, there is an element in this
1318               list, which is itself a list of all the attribute values
1319               in the tuple.
1320             </para>
1321           </listitem>
1322         </varlistentry>
1323       </variablelist>
1324     </refsect1>
1325     <refsect1>
1326       <title>Description</title>
1327       <para>
1328         Executes a query on <parameter>database</parameter>, which has
1329         a default value of <symbol>*default-database*</symbol>,
1330         specified by the SQL expressions supplied using the remaining
1331         arguments in <parameter>args</parameter>. The
1332         <function>select</function> function can be used to generate
1333         queries in both functional and object oriented contexts.
1334       </para>
1335       <para>
1336         In the functional case, the required arguments specify the
1337         columns selected by the query and may be symbolic SQL
1338         expressions or strings representing attribute
1339         identifiers. Type modified identifiers indicate that the
1340         values selected from the specified column are converted to the
1341         specified lisp type. The keyword arguments
1342         <parameter>all</parameter>, <parameter>distinct</parameter>,
1343         <parameter>from</parameter>, <parameter>group-by</parameter>,
1344         <parameter>having</parameter>,
1345         <parameter>order-by</parameter>,
1346         <parameter>set-operation</parameter> and
1347         <parameter>where</parameter> are used to specify, using the
1348         symbolic SQL syntax, the corresponding components of the SQL
1349         query generated by the call to
1350         <function>select</function>.
1351       </para>
1352       <para>
1353         <parameter>result-types</parameter> is a list of symbols which
1354         specifies the lisp type for each field returned by the
1355         query. If <parameter>result-types</parameter> is &nil; all
1356         results are returned as strings whereas the default value of
1357         <symbol>:auto</symbol> means that the lisp types are
1358         automatically computed for each
1359         field. <parameter>field-names</parameter> is &t; by default
1360         which means that the second value returned is a list of
1361         strings representing the columns selected by the query. If
1362         <parameter>field-names</parameter> is &nil;, the list of
1363         column names is not returned as a second value.
1364       </para>
1365       <para>
1366         In the object oriented case, the required arguments to
1367         <function>select</function> are symbols denoting View Classes
1368         which specify the database tables to query. In this case,
1369         <function>select</function> returns a list of View Class
1370         instances whose slots are set from the attribute values of the
1371         records in the specified table. <symbol>Slot-value</symbol> is
1372         a legal operator which can be employed as part of the symbolic
1373         SQL syntax used in the <parameter>where</parameter> keyword
1374         argument to <function>select</function>.
1375         <parameter>refresh</parameter> is &nil; by default which means
1376         that the View Class instances returned are retrieved from a
1377         cache if an equivalent call to <function>select</function> has
1378         previously been issued. If <parameter>refresh</parameter> is
1379         true, the View Class instances returned are updated as
1380         necessary from the database and the generic function
1381         <function>instance-refreshed</function> is called to perform
1382         any necessary operations on the updated instances.
1383       </para>
1384       <para>
1385         In both object oriented and functional contexts,
1386         <parameter>flatp</parameter> has a default value of &nil;
1387         which means that the results are returned as a list of
1388         lists. If <parameter>flatp</parameter> is t and only one
1389         result is returned for each record selected in the query, the
1390         results are returned as elements of a list.
1391       </para>
1392     </refsect1>
1393     <refsect1>
1394       <title>Examples</title>
1395       <screen>
1396 (select [first-name] :from [employee] :flatp t :distinct t
1397                      :field-names nil
1398                      :result-types nil
1399                      :order-by [first-name])
1400 => ("Boris" "Josef" "Konstantin" "Leon" "Leonid" "Mikhail" "Nikita" "Vladimir"
1401     "Yuri")
1402
1403 (select [first-name] [count [*]] :from [employee]
1404                                  :result-types nil
1405                                  :group-by [first-name]
1406                                  :order-by [first-name]
1407                                  :field-names nil)
1408 => (("Boris" "1") ("Josef" "1") ("Konstantin" "1") ("Leon" "1") ("Leonid" "1")
1409     ("Mikhail" "1") ("Nikita" "1") ("Vladimir" "2") ("Yuri" "1"))
1410
1411 (select [last-name] :from [employee]
1412                     :where [like [email] "%org"]
1413                     :order-by [last-name]
1414                     :field-names nil
1415                     :result-types nil
1416                     :flatp t)
1417 => ("Andropov" "Brezhnev" "Chernenko" "Gorbachev" "Kruschev" "Lenin" "Putin"
1418     "Stalin" "Trotsky" "Yeltsin")
1419
1420 (select [max [emplid]] :from [employee]
1421                        :flatp t
1422                        :field-names nil
1423                        :result-types :auto)
1424 => (10)
1425
1426 (clsql:select [avg [height]] :from [employee] :flatp t :field-names nil)
1427 => (1.58999584d0)
1428
1429 (select [emplid] [last-name] :from [employee] :where [= [emplid] 1])
1430 => ((1 "Lenin")),
1431    ("emplid" "last_name")
1432
1433 (select [emplid :string] :from [employee]
1434                          :where [= 1 [emplid]]
1435                          :field-names nil
1436                          :flatp t)
1437 => ("1")
1438
1439 (select [emplid] :from [employee] :order-by [emplid]
1440                  :where [not [between [* [emplid] 10] [* 5 10] [* 10 10]]]
1441                  :field-names nil
1442                  :flatp t)
1443 => (1 2 3 4)
1444
1445 (clsql:select [emplid] :from [employee]
1446                        :where [in [emplid] '(1 2 3 4)]
1447                        :flatp t
1448                        :order-by [emplid]
1449                        :field-names nil)
1450 => (1 2 3 4)
1451
1452 (select [first-name] [last-name] :from [employee]
1453         :field-names nil
1454         :order-by '(([first-name] :asc) ([last-name] :desc)))
1455 => (("Boris" "Yeltsin") ("Josef" "Stalin") ("Konstantin" "Chernenko")
1456     ("Leon" "Trotsky") ("Leonid" "Brezhnev") ("Mikhail" "Gorbachev")
1457     ("Nikita" "Kruschev") ("Vladimir" "Putin") ("Vladimir" "Lenin")
1458     ("Yuri" "Andropov"))
1459
1460 (select [last-name] :from [employee]
1461                  :set-operation [union [select [first-name] :from [employee]
1462                                                :order-by [last-name]]]
1463                  :flatp t
1464                  :result-types nil
1465                  :field-names nil)
1466 => ("Andropov" "Boris" "Brezhnev" "Chernenko" "Gorbachev" "Josef" "Konstantin"
1467     "Kruschev" "Lenin" "Leon" "Leonid" "Mikhail" "Nikita" "Putin" "Stalin"
1468     "Trotsky" "Vladimir" "Yeltsin" "Yuri")
1469       </screen>
1470     </refsect1>
1471     <refsect1>
1472       <title>Side Effects</title>
1473         <para>Whatever effects the execution of the SQL query has on
1474         the underlying database, if any.</para>
1475     </refsect1>
1476     <refsect1>
1477       <title>Affected by</title>
1478       <para>
1479         None.
1480       </para>
1481     </refsect1>
1482     <refsect1>
1483       <title>Exceptional Situations</title>
1484       <para>
1485         If the execution of the SQL query leads to any errors, an
1486         error of type <errortype>sql-database-error</errortype> is
1487         signalled.
1488       </para>
1489     </refsect1>
1490     <refsect1>
1491       <title>See Also</title>
1492       <simplelist>
1493         <member><link linkend="query"><function>query</function></link></member>
1494         <member><link linkend="print-query"><function>print-query</function></link></member>
1495         <member><link linkend="do-query"><function>do-query</function></link></member>
1496         <member><link linkend="map-query"><function>map-query</function></link></member>
1497         <member><link linkend="loop-tuples"><function>loop</function></link></member>
1498         <member><link linkend="instance-refreshed"><function>instance-refreshed</function></link></member>
1499       </simplelist>
1500     </refsect1>
1501     <refsect1>
1502       <title>Notes</title>
1503       <para>
1504         The <function>select</function> function is actually
1505         implemented in &clsql; with a single
1506         <symbol>&amp;rest</symbol> parameter (which is subsequently
1507         destructured) rather than the keyword parameters presented
1508         here for the purposes of exposition. This means that incorrect
1509         or missing keywords or values may not trigger errors in the
1510         way that they would if <function>select</function> had been
1511         defined using keyword arguments.
1512       </para>
1513       <para>
1514         The <parameter>field-names</parameter> and
1515         <parameter>result-types</parameter> keyword arguments are a
1516         &clsql; extension.
1517       </para>
1518       <para>
1519         <parameter>select</parameter> is common across the functional
1520         and object-oriented data manipulation languages.
1521       </para>
1522     </refsect1>
1523   </refentry>
1524
1525
1526   <!-- iteration and mapping -->
1527
1528   <refentry id="do-query">
1529     <refmeta>
1530       <refentrytitle>DO-QUERY</refentrytitle>
1531     </refmeta>
1532     <refnamediv>
1533       <refname>DO-QUERY</refname>
1534       <refpurpose>Iterate over all the tuples of a query.</refpurpose>
1535       <refclass>Macro</refclass>
1536     </refnamediv>
1537     <refsect1>
1538       <title>Syntax</title>
1539       <synopsis>
1540       <function>do-query</function> ((&amp;rest <replaceable>args</replaceable>) <replaceable>query-expression</replaceable> &amp;key <replaceable>database</replaceable> <replaceable>result-types</replaceable> &amp;body <replaceable>body</replaceable> => <returnvalue>result</returnvalue></synopsis>
1541     </refsect1>
1542     <refsect1>
1543       <title>Arguments and Values</title>
1544       <variablelist>
1545         <varlistentry>
1546           <term><parameter>args</parameter></term>
1547           <listitem>
1548             <para>A list of variable names.</para>
1549           </listitem>
1550         </varlistentry>
1551         <varlistentry>
1552           <term><parameter>query-expression</parameter></term>
1553           <listitem>
1554             <para>An <glossterm linkend="gloss-sql-expression">sql
1555             expression</glossterm> that represents an SQL
1556             query which is expected to return a (possibly empty)
1557             result set, where each tuple has as many attributes as
1558             <parameter>function</parameter> takes arguments.</para>
1559           </listitem>
1560         </varlistentry>
1561         <varlistentry>
1562           <term><parameter>database</parameter></term>
1563           <listitem>
1564             <para>A
1565             <glossterm linkend="gloss-database-object">database
1566             object</glossterm>. This will default to
1567             <symbol>*default-database*</symbol>.</para>
1568           </listitem>
1569         </varlistentry>
1570         <varlistentry>
1571           <term><parameter>result-types</parameter></term>
1572           <listitem>
1573             <para>
1574               A <glossterm linkend="gloss-field-types">field type
1575               specifier</glossterm>.  The default is &nil;. See <link
1576               linkend="query"><function>query</function></link> for
1577               the semantics of this argument.
1578             </para>
1579           </listitem>
1580         </varlistentry>
1581         <varlistentry>
1582           <term><parameter>body</parameter></term>
1583           <listitem>
1584             <para>A body of Lisp code, like in a
1585             <function>destructuring-bind</function> form.</para>
1586           </listitem>
1587         </varlistentry>
1588         <varlistentry>
1589           <term><parameter>result</parameter></term>
1590           <listitem>
1591             <para>The result of executing <parameter>body</parameter>.</para>
1592           </listitem>
1593         </varlistentry>
1594       </variablelist>
1595     </refsect1>
1596     <refsect1>
1597       <title>Description</title>
1598       <para>
1599         Repeatedly executes <parameter>body</parameter> within a
1600         binding of <parameter>args</parameter> on the fields of each
1601         row selected by the SQL query
1602         <parameter>query-expression</parameter>, which may be a string
1603         or a symbolic SQL expression, in
1604         <parameter>database</parameter> which defaults to
1605         <symbol>*default-database*</symbol>.
1606       </para>
1607       <para>
1608         The body of code is executed in a block named
1609         <symbol>nil</symbol> which may be returned from prematurely
1610         via <function>return</function> or
1611         <function>return-from</function>.  In this case the result of
1612         evaluating the <function>do-query</function> form will be the
1613         one supplied to <function>return</function> or
1614         <function>return-from</function>.  Otherwise the result will
1615         be <symbol>nil</symbol>.
1616       </para>
1617       <para>
1618         The body of code appears also is if wrapped in a
1619         <function>destructuring-bind</function> form, thus allowing
1620         declarations at the start of the body, especially those
1621         pertaining to the bindings of the variables named in
1622         <parameter>args</parameter>.
1623       </para>
1624       <para>
1625         <parameter>result-types</parameter> is a list of symbols which
1626         specifies the lisp type for each field returned by
1627         <parameter>query-expression</parameter>. If
1628         <parameter>result-types</parameter> is &nil; all results are
1629         returned as strings whereas the default value of
1630         <symbol>:auto</symbol> means that the lisp types are
1631         automatically computed for each field.
1632       </para>
1633       <para>
1634         <parameter>query-expression</parameter> may be an object query
1635         (i.e., the selection arguments refer to View Classes), in
1636         which case <parameter>args</parameter> are bound to the tuples
1637         of View Class instances returned by the object oriented query.
1638       </para>
1639     </refsect1>
1640     <refsect1>
1641       <title>Examples</title>
1642       <screen>
1643 (do-query ((salary name) "select salary,name from simple")
1644   (format t "~30A gets $~2,5$~%" name (read-from-string salary)))
1645 >> Mai, Pierre                    gets $10000.00
1646 >> Hacker, Random J.              gets $08000.50
1647 => NIL
1648
1649 (do-query ((salary name) "select salary,name from simple")
1650   (return (cons salary name)))
1651 => ("10000.00" . "Mai, Pierre")
1652
1653 (let ((result '()))
1654   (do-query ((name) [select [last-name] :from [employee]
1655                             :order-by [last-name]])
1656     (push name result))
1657   result)
1658 => ("Yeltsin" "Trotsky" "Stalin" "Putin" "Lenin" "Kruschev" "Gorbachev"
1659     "Chernenko" "Brezhnev" "Andropov")
1660
1661 (let ((result '()))
1662   (do-query ((e) [select 'employee :order-by [last-name]])
1663     (push (slot-value e 'last-name) result))
1664   result)
1665 => ("Yeltsin" "Trotsky" "Stalin" "Putin" "Lenin" "Kruschev" "Gorbachev"
1666     "Chernenko" "Brezhnev" "Andropov")
1667       </screen>
1668     </refsect1>
1669     <refsect1>
1670       <title>Side Effects</title>
1671       <para>Whatever effects the execution of the SQL query has
1672       on the underlying database, if any.</para>
1673     </refsect1>
1674     <refsect1>
1675       <title>Affected by</title>
1676       <para>None.</para>
1677     </refsect1>
1678     <refsect1>
1679       <title>Exceptional Situations</title>
1680       <para>If the execution of  the SQL query leads to any
1681       errors, an error of type
1682       <errortype>sql-database-error</errortype> is signalled.</para>
1683       <para>If the number of variable names in
1684       <parameter>args</parameter> and the number of attributes in
1685       the tuples in the result set don't match up, an error is
1686       signalled.</para>
1687     </refsect1>
1688     <refsect1>
1689       <title>See Also</title>
1690       <simplelist>
1691         <member><link linkend="query"><function>query</function></link></member>
1692         <member><link linkend="map-query"><function>map-query</function></link></member>
1693         <member><link linkend="print-query"><function>print-query</function></link></member>
1694         <member><link linkend="loop-tuples"><function>loop</function></link></member>
1695         <member><link linkend="select"><function>select</function></link></member>
1696       </simplelist>
1697     </refsect1>
1698     <refsect1>
1699       <title>Notes</title>
1700       <para>The <parameter>result-types</parameter> keyword argument
1701       is a &clsql; extension.</para>
1702       <para>
1703         <parameter>do-query</parameter> is common across the functional
1704         and object-oriented data manipulation languages.
1705       </para>
1706     </refsect1>
1707   </refentry>
1708
1709   <refentry id="loop-tuples">
1710     <refmeta>
1711       <refentrytitle>LOOP</refentrytitle>
1712     </refmeta>
1713     <refnamediv>
1714       <refname>LOOP</refname>
1715       <refpurpose>Extension to Common Lisp
1716       <computeroutput>Loop</computeroutput> to iterate over all the
1717       tuples of a query via a loop clause.</refpurpose>
1718       <refclass>Loop Clause</refclass>
1719     </refnamediv>
1720     <!-- refsect1>
1721       <title>Compatibility</title>
1722       <caution><para><function>loop-for-as-tuples</function> only works with &cmucl;.</para></caution>
1723     </refsect1 -->
1724     <refsect1>
1725       <title>Syntax</title>
1726       <synopsis>{as | for} <replaceable>var</replaceable> [<replaceable>type-spec</replaceable>] being {each | the} {record | records | tuple | tuples} {in | of} <replaceable>query</replaceable> [from <replaceable>database</replaceable>]</synopsis>
1727     </refsect1>
1728     <refsect1>
1729       <title>Arguments and Values</title>
1730       <variablelist>
1731         <varlistentry>
1732           <term><parameter>var</parameter></term>
1733           <listitem>
1734             <para>A <literal>d-var-spec</literal>, as defined in the
1735             grammar for <function>loop</function>-clauses in the ANSI
1736             Standard for Common Lisp.  This allows for the usual
1737             loop-style destructuring.</para>
1738           </listitem>
1739         </varlistentry>
1740         <varlistentry>
1741           <term><parameter>type-spec</parameter></term>
1742           <listitem>
1743             <para>An optional <literal>type-spec</literal> either
1744             simple or destructured, as defined in the grammar for
1745             <function>loop</function>-clauses in the ANSI Standard for
1746             Common Lisp.</para>
1747           </listitem>
1748         </varlistentry>
1749         <varlistentry>
1750           <term><parameter>query</parameter></term>
1751           <listitem>
1752             <para>An <glossterm linkend="gloss-sql-expression">sql
1753             expression</glossterm> that represents an SQL
1754             query which is expected to return a (possibly empty)
1755             result set, where each tuple has as many attributes as
1756             <parameter>function</parameter> takes arguments.</para>
1757           </listitem>
1758         </varlistentry>
1759         <varlistentry>
1760           <term><parameter>database</parameter></term>
1761           <listitem>
1762             <para>An optional
1763             <glossterm linkend="gloss-database-object">database
1764             object</glossterm>. This will default to the value
1765             of <symbol>*default-database*</symbol>.</para>
1766           </listitem>
1767         </varlistentry>
1768       </variablelist>
1769     </refsect1>
1770     <refsect1>
1771       <title>Description</title>
1772       <para>This clause is an iteration driver for
1773       <function>loop</function>, that binds the given variable
1774       (possibly destructured) to the consecutive tuples (which are
1775       represented as lists of attribute values) in the result set
1776       returned by executing the SQL <parameter>query</parameter>
1777       expression on the <parameter>database</parameter>
1778       specified.</para>
1779       <para>
1780         <parameter>query</parameter> may be an object query (i.e., the
1781         selection arguments refer to View Classes), in which case the
1782         supplied variable is bound to the tuples of View Class
1783         instances returned by the object oriented query.
1784       </para>
1785     </refsect1>
1786     <refsect1>
1787       <title>Examples</title>
1788       <screen>
1789 (defvar *my-db* (connect '("dent" "newesim" "dent" "dent"))
1790 "My database"
1791 => *MY-DB*
1792 (loop with time-graph = (make-hash-table :test #'equal)
1793    with event-graph = (make-hash-table :test #'equal)
1794    for (time event) being the tuples of "select time,event from log"
1795    from *my-db*
1796    do
1797      (incf (gethash time time-graph 0))
1798      (incf (gethash event event-graph 0))
1799    finally
1800      (flet ((show-graph (k v) (format t "~40A => ~5D~%" k v)))
1801        (format t "~&amp;Time-Graph:~%===========~%")
1802        (maphash #'show-graph time-graph)
1803        (format t "~&amp;~%Event-Graph:~%============~%")
1804        (maphash #'show-graph event-graph))
1805      (return (values time-graph event-graph)))
1806 >> Time-Graph:
1807 >> ===========
1808 >> D                                        => 53000
1809 >> X                                        =>     3
1810 >> test-me                                  =>  3000
1811 >>
1812 >> Event-Graph:
1813 >> ============
1814 >> CLOS Benchmark entry.                    =>  9000
1815 >> Demo Text...                             =>     3
1816 >> doit-text                                =>  3000
1817 >> C    Benchmark entry.                    => 12000
1818 >> CLOS Benchmark entry                     => 32000
1819 => #&lt;EQUAL hash table, 3 entries {48350A1D}>
1820 => #&lt;EQUAL hash table, 5 entries {48350FCD}>
1821
1822 (loop for (forename surname)
1823       being each tuple in
1824         [select [first-name] [last-name] :from [employee]
1825                 :order-by [last-name]]
1826       collect (concatenate 'string forename " " surname))
1827 => ("Yuri Andropov" "Leonid Brezhnev" "Konstantin Chernenko" "Mikhail Gorbachev"
1828     "Nikita Kruschev" "Vladimir Lenin" "Vladimir Putin" "Josef Stalin"
1829     "Leon Trotsky" "Boris Yeltsin")
1830
1831 (loop for (e) being the records in
1832      [select 'employee :where [&lt; [emplid] 4] :order-by [emplid]]
1833   collect (slot-value e 'last-name))
1834 => ("Lenin" "Stalin" "Trotsky")
1835       </screen>
1836     </refsect1>
1837     <refsect1>
1838       <title>Side Effects</title>
1839       <para>Whatever effects the execution of the SQL query has
1840       on the underlying database, if any.</para>
1841     </refsect1>
1842     <refsect1>
1843       <title>Affected by</title>
1844       <para>None.</para>
1845     </refsect1>
1846     <refsect1>
1847       <title>Exceptional Situations</title>
1848       <para>If the execution of  the SQL query leads to any
1849       errors, an error of type
1850       <errortype>sql-database-error</errortype> is signalled.</para>
1851       <para>Otherwise, any of the exceptional situations of
1852       <function>loop</function> applies.</para>
1853     </refsect1>
1854     <refsect1>
1855       <title>See Also</title>
1856       <para>
1857         <simplelist>
1858           <member><link linkend="query"><function>query</function></link></member>
1859           <member><link linkend="map-query"><function>map-query</function></link></member>
1860           <member><link linkend="do-query"><function>do-query</function></link></member>
1861         <member><link linkend="print-query"><function>print-query</function></link></member>
1862         <member><link linkend="select"><function>select</function></link></member>
1863         </simplelist>
1864       </para>
1865     </refsect1>
1866     <refsect1>
1867       <title>Notes</title>
1868       <para>The <parameter>database</parameter> loop keyword is a
1869       &clsql; extension.</para>
1870       <para>
1871         The extended <function>loop</function> syntax is common across
1872         the functional and object-oriented data manipulation
1873         languages.
1874       </para>
1875     </refsect1>
1876   </refentry>
1877
1878   <refentry id="map-query">
1879     <refmeta>
1880       <refentrytitle>MAP-QUERY</refentrytitle>
1881     </refmeta>
1882     <refnamediv>
1883       <refname>MAP-QUERY</refname>
1884       <refpurpose>Map a function over all the tuples from a
1885       query</refpurpose>
1886       <refclass>Function</refclass>
1887     </refnamediv>
1888     <refsect1>
1889       <title>Syntax</title>
1890       <synopsis><function>map-query</function> <replaceable>output-type-spec</replaceable> <replaceable>function</replaceable> <replaceable>query-expression</replaceable> &amp;key <replaceable>database</replaceable> <replaceable>result-types</replaceable> => <returnvalue>result</returnvalue></synopsis>
1891     </refsect1>
1892     <refsect1>
1893       <title>Arguments and Values</title>
1894       <variablelist>
1895         <varlistentry>
1896           <term><parameter>output-type-spec</parameter></term>
1897           <listitem>
1898             <para>A sequence type specifier or <symbol>nil</symbol>.</para>
1899           </listitem>
1900         </varlistentry>
1901         <varlistentry>
1902           <term><parameter>function</parameter></term>
1903           <listitem>
1904             <para>A function designator.
1905             <parameter>function</parameter> takes a single argument which
1906             is the atom value for a query single with a single column
1907             or is a list of values for a multi-column query.</para>
1908           </listitem>
1909         </varlistentry>
1910         <varlistentry>
1911           <term><parameter>query-expression</parameter></term>
1912           <listitem>
1913             <para>An <glossterm linkend="gloss-sql-expression">sql
1914             expression</glossterm> that represents an SQL
1915             query which is expected to return a (possibly empty)
1916             result set.</para>
1917           </listitem>
1918         </varlistentry>
1919         <varlistentry>
1920           <term><parameter>database</parameter></term>
1921           <listitem>
1922             <para>A
1923             <glossterm linkend="gloss-database-object">database
1924             object</glossterm>. This will default to the value
1925             of <symbol>*default-database*</symbol>.</para>
1926           </listitem>
1927         </varlistentry>
1928         <varlistentry>
1929           <term><parameter>result-types</parameter></term>
1930           <listitem>
1931             <para>
1932               A <glossterm linkend="gloss-field-types">field type
1933               specifier</glossterm>.  The default is &nil;. See <link
1934               linkend="query"><function>query</function></link> for
1935               the semantics of this argument.
1936             </para>
1937           </listitem>
1938         </varlistentry>
1939         <varlistentry>
1940           <term><returnvalue>result</returnvalue></term>
1941           <listitem>
1942             <para>If <parameter>output-type-spec</parameter> is a
1943             type specifier other than <symbol>nil</symbol>, then a
1944             sequence of the type it denotes.  Otherwise
1945             <symbol>nil</symbol> is returned.</para>
1946           </listitem>
1947         </varlistentry>
1948       </variablelist>
1949     </refsect1>
1950     <refsect1>
1951       <title>Description</title>
1952       <para>
1953         Applies <parameter>function</parameter> to the successive
1954         tuples in the result set returned by executing the SQL
1955         <parameter>query-expression</parameter>.  If the
1956         <parameter>output-type-spec</parameter> is
1957         <symbol>nil</symbol>, then the result of each application of
1958         <parameter>function</parameter> is discarded, and
1959         <function>map-query</function> returns <symbol>nil</symbol>.
1960         Otherwise the result of each successive application of
1961         <parameter>function</parameter> is collected in a sequence of
1962         type <parameter>output-type-spec</parameter>, where the jths
1963         element is the result of applying
1964         <parameter>function</parameter> to the attributes of the jths
1965         tuple in the result set.  The collected sequence is the result
1966         of the call to <function>map-query</function>.
1967       </para>
1968       <para>
1969         If the <parameter>output-type-spec</parameter> is a subtype of
1970         <type>list</type>, the result will be a <type>list</type>.
1971       </para>
1972       <para>
1973         If the <parameter>result-type</parameter> is a subtype of
1974         <type>vector</type>, then if the implementation can determine
1975         the element type specified for the
1976         <parameter>result-type</parameter>, the element type of the
1977         resulting array is the result of
1978         <emphasis>upgrading</emphasis> that element type; or, if the
1979         implementation can determine that the element type is
1980         unspecified (or <symbol>*</symbol>), the element type of the
1981         resulting array is <type>t</type>; otherwise, an error is
1982         signaled.
1983       </para>
1984       <para>
1985         If <parameter>result-types</parameter> is &nil; all results
1986         are returned as strings whereas the default value of
1987         <symbol>:auto</symbol> means that the lisp types are
1988         automatically computed for each field.</para>
1989       <para>
1990         <parameter>query-expression</parameter> may be an object query
1991         (i.e., the selection arguments refer to View Classes), in
1992         which case the supplied function is applied to the tuples of
1993         View Class instances returned by the object oriented query.
1994       </para>
1995     </refsect1>
1996     <refsect1>
1997       <title>Examples</title>
1998       <screen>
1999 (map-query 'list #'(lambda (tuple)
2000                      (multiple-value-bind (salary name) tuple
2001                         (declare (ignorable name))
2002                         (read-from-string salary)))
2003             "select salary,name from simple where salary > 8000")
2004 => (10000.0 8000.5)
2005
2006 (map-query '(vector double-float)
2007            #'(lambda (tuple)
2008                (multiple-value-bind (salary name) tuple
2009                   (declare (ignorable name))
2010                   (let ((*read-default-float-format* 'double-float))
2011                     (coerce (read-from-string salary) 'double-float))
2012            "select salary,name from simple where salary > 8000")))
2013 => #(10000.0d0 8000.5d0)
2014 (type-of *)
2015 => (SIMPLE-ARRAY DOUBLE-FLOAT (2))
2016
2017 (let (list)
2018   (values (map-query nil #'(lambda (tuple)
2019                              (multiple-value-bind (salary name) tuple
2020                                (push (cons name (read-from-string salary)) list))
2021                          "select salary,name from simple where salary > 8000"))
2022           list))
2023 => NIL
2024 => (("Hacker, Random J." . 8000.5) ("Mai, Pierre" . 10000.0))
2025
2026 (map-query 'vector #'identity
2027            [select [last-name] :from [employee] :flatp t
2028                    :order-by [last-name]])
2029 => #("Andropov" "Brezhnev" "Chernenko" "Gorbachev" "Kruschev" "Lenin" "Putin"
2030      "Stalin" "Trotsky" "Yeltsin")
2031
2032 (map-query 'list #'identity
2033            [select [first-name] [last-name] :from [employee]
2034                    :order-by [last-name]])
2035 => (("Yuri" "Andropov") ("Leonid" "Brezhnev") ("Konstantin" "Chernenko")
2036     ("Mikhail" "Gorbachev") ("Nikita" "Kruschev") ("Vladimir" "Lenin")
2037     ("Vladimir" "Putin") ("Josef" "Stalin") ("Leon" "Trotsky")
2038     ("Boris" "Yeltsin"))
2039
2040 (map-query 'list #'last-name [select 'employee :order-by [emplid]])
2041 => ("Lenin" "Stalin" "Trotsky" "Kruschev" "Brezhnev" "Andropov" "Chernenko"
2042     "Gorbachev" "Yeltsin" "Putin")
2043       </screen>
2044     </refsect1>
2045     <refsect1>
2046       <title>Side Effects</title>
2047       <para>Whatever effects the execution of the SQL query has
2048       on the underlying database, if any.</para>
2049     </refsect1>
2050     <refsect1>
2051       <title>Affected by</title>
2052       <para>None.</para>
2053     </refsect1>
2054     <refsect1>
2055       <title>Exceptional Situations</title>
2056       <para>If the execution of  the SQL query leads to any
2057       errors, an error of type
2058       <errortype>sql-database-error</errortype> is signalled.</para>
2059       <para>An error of type <errortype>type-error</errortype> must
2060       be signaled if the <parameter>output-type-spec</parameter> is
2061       not a recognizable subtype of <type>list</type>, not a
2062       recognizable subtype of <type>vector</type>, and not
2063       <symbol>nil</symbol>.</para>
2064       <para>An error of type <errortype>type-error</errortype>
2065       should be signaled if
2066       <parameter>output-type-spec</parameter> specifies the number
2067       of elements and the size of the result set is different from
2068       that number.</para>
2069     </refsect1>
2070     <refsect1>
2071       <title>See Also</title>
2072       <simplelist>
2073         <member><link linkend="query"><function>query</function></link></member>
2074         <member><link linkend="do-query"><function>do-query</function></link></member>
2075         <member><link linkend="print-query"><function>print-query</function></link></member>
2076         <member><link linkend="loop-tuples"><function>loop</function></link></member>
2077         <member><link linkend="select"><function>select</function></link></member>
2078       </simplelist>
2079     </refsect1>
2080     <refsect1>
2081       <title>Notes</title>
2082       <para>The <parameter>result-types</parameter> keyword argument
2083       is a &clsql; extension.</para>
2084       <para>
2085         <parameter>map-query</parameter> is common across the
2086         functional and object-oriented data manipulation languages.
2087       </para>
2088     </refsect1>
2089   </refentry>
2090
2091 </reference>
2092