1 ;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10 -*-
2 ;;;; *************************************************************************
6 ;;;; The CLSQL Object Oriented Data Definitional Language (OODDL)
8 ;;;; This file is part of CLSQL.
10 ;;;; CLSQL users are granted the rights to distribute and use this software
11 ;;;; as governed by the terms of the Lisp Lesser GNU Public License
12 ;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
13 ;;;; *************************************************************************
16 (in-package #:clsql-sys)
18 (defclass standard-db-object ()
19 ((view-database :initform nil :initarg :view-database :reader view-database
21 (:metaclass standard-db-class)
22 (:documentation "Superclass for all CLSQL View Classes."))
24 (defparameter *default-string-length* 255
25 "The length of a string which does not have a user-specified length.")
27 (defvar *db-auto-sync* nil
28 "A non-nil value means that creating View Class instances or
29 setting their slots automatically creates/updates the
30 corresponding records in the underlying database.")
32 (defvar *db-deserializing* nil)
33 (defvar *db-initializing* nil)
35 (defmethod slot-value-using-class ((class standard-db-class) instance slot-def)
36 (declare (optimize (speed 3)))
37 (unless *db-deserializing*
38 (let* ((slot-name (%svuc-slot-name slot-def))
39 (slot-object (%svuc-slot-object slot-def class))
40 (slot-kind (view-class-slot-db-kind slot-object)))
41 (when (and (eql slot-kind :join)
42 (not (slot-boundp instance slot-name)))
43 (let ((*db-deserializing* t))
44 (if (view-database instance)
45 (setf (slot-value instance slot-name)
46 (fault-join-slot class instance slot-object))
47 (setf (slot-value instance slot-name) nil))))))
50 (defmethod (setf slot-value-using-class) (new-value (class standard-db-class)
52 (declare (ignore new-value))
53 (let* ((slot-name (%svuc-slot-name slot-def))
54 (slot-object (%svuc-slot-object slot-def class))
55 (slot-kind (view-class-slot-db-kind slot-object)))
58 (when (and *db-auto-sync*
59 (not *db-initializing*)
60 (not *db-deserializing*)
61 (not (eql slot-kind :virtual)))
62 (update-record-from-slot instance slot-name)))))
64 (defmethod initialize-instance ((object standard-db-object)
65 &rest all-keys &key &allow-other-keys)
66 (declare (ignore all-keys))
67 (let ((*db-initializing* t))
69 (when (and *db-auto-sync*
70 (not *db-deserializing*))
71 (update-records-from-instance object))))
74 ;; Build the database tables required to store the given view class
77 (defun create-view-from-class (view-class-name
78 &key (database *default-database*)
80 "Creates a table as defined by the View Class VIEW-CLASS-NAME
81 in DATABASE which defaults to *DEFAULT-DATABASE*."
82 (let ((tclass (find-class view-class-name)))
84 (let ((*default-database* database))
85 (%install-class tclass database :transactions transactions))
86 (error "Class ~s not found." view-class-name)))
89 (defmethod %install-class ((self standard-db-class) database
90 &key (transactions t))
91 (let ((schemadef '()))
92 (dolist (slotdef (ordered-class-slots self))
93 (let ((res (database-generate-column-definition (class-name self)
96 (push res schemadef))))
98 (error "Class ~s has no :base slots" self))
99 (create-table (sql-expression :table (view-table self)) (nreverse schemadef)
101 :transactions transactions
102 :constraints (database-pkey-constraint self database))
103 (push self (database-view-classes database)))
106 (defmethod database-pkey-constraint ((class standard-db-class) database)
107 (let ((keylist (mapcar #'view-class-slot-column (keyslots-for-class class)))
108 (table (view-table class)))
112 (format nil "CONSTRAINT \"~APK\" PRIMARY KEY~A" table
113 (sql-output keylist database)))
114 ((or symbol sql-ident)
115 (format nil "CONSTRAINT ~APK PRIMARY KEY~A" table
116 (sql-output keylist database)))))))
118 (defmethod database-generate-column-definition (class slotdef database)
119 (declare (ignore database class))
120 (when (member (view-class-slot-db-kind slotdef) '(:base :key))
122 (list (sql-expression :attribute (view-class-slot-column slotdef))
123 (specified-type slotdef))))
124 (setf cdef (append cdef (list (view-class-slot-db-type slotdef))))
125 (let ((const (view-class-slot-db-constraints slotdef)))
127 (setq cdef (append cdef (listify const)))))
132 ;; Drop the tables which store the given view class
135 (defun drop-view-from-class (view-class-name &key (database *default-database*)
137 "Removes a table defined by the View Class VIEW-CLASS-NAME from
138 DATABASE which defaults to *DEFAULT-DATABASE*."
139 (let ((tclass (find-class view-class-name)))
141 (let ((*default-database* database))
142 (%uninstall-class tclass :owner owner))
143 (error "Class ~s not found." view-class-name)))
146 (defun %uninstall-class (self &key
147 (database *default-database*)
149 (drop-table (sql-expression :table (view-table self))
150 :if-does-not-exist :ignore
153 (setf (database-view-classes database)
154 (remove self (database-view-classes database))))
158 ;; List all known view classes
161 (defun list-classes (&key (test #'identity)
162 (root-class (find-class 'standard-db-object))
163 (database *default-database*))
164 "Returns a list of all the View Classes which are connected to
165 DATABASE, which defaults to *DEFAULT-DATABASE*, and which descend
166 from the class ROOT-CLASS and which satisfy the function TEST. By
167 default ROOT-CLASS is STANDARD-DB-OBJECT and TEST is IDENTITY."
168 (flet ((find-superclass (class)
169 (member root-class (class-precedence-list class))))
170 (let ((view-classes (and database (database-view-classes database))))
172 (remove-if #'(lambda (c) (or (not (funcall test c))
173 (not (find-superclass c))))
177 ;; Define a new view class
180 (defmacro def-view-class (class supers slots &rest cl-options)
181 "Creates a View Class called CLASS whose slots SLOTS can map
182 onto the attributes of a table in a database. If SUPERS is nil
183 then the superclass of CLASS will be STANDARD-DB-OBJECT,
184 otherwise SUPERS is a list of superclasses for CLASS which must
185 include STANDARD-DB-OBJECT or a descendent of this class. The
186 syntax of DEFCLASS is extended through the addition of a class
187 option :base-table which defines the database table onto which
188 the View Class maps and which defaults to CLASS. The DEFCLASS
189 syntax is also extended through additional slot
190 options. The :db-kind slot option specifies the kind of DB
191 mapping which is performed for this slot and defaults to :base
192 which indicates that the slot maps to an ordinary column of the
193 database table. A :db-kind value of :key indicates that this slot
194 is a special kind of :base slot which maps onto a column which is
195 one of the unique keys for the database table, the value :join
196 indicates this slot represents a join onto another View Class
197 which contains View Class objects, and the value :virtual
198 indicates a standard CLOS slot which does not map onto columns of
199 the database table. If a slot is specified with :db-kind :join,
200 the slot option :db-info contains a list which specifies the
201 nature of the join. For slots of :db-kind :base or :key,
202 the :type slot option has a special interpretation such that Lisp
203 types, such as string, integer and float are automatically
204 converted into appropriate SQL types for the column onto which
205 the slot maps. This behaviour may be over-ridden using
206 the :db-type slot option which is a string specifying the
207 vendor-specific database type for this slot's column definition
208 in the database. The :column slot option specifies the name of
209 the SQL column which the slot maps onto, if :db-kind is
210 not :virtual, and defaults to the slot name. The :void-value slot
211 option specifies the value to store if the SQL value is NULL and
212 defaults to NIL. The :db-constraints slot option is a string
213 representing an SQL table constraint expression or a list of such
216 (defclass ,class ,supers ,slots
217 ,@(if (find :metaclass `,cl-options :key #'car)
219 (cons '(:metaclass clsql-sys::standard-db-class) `,cl-options)))
220 (finalize-inheritance (find-class ',class))
221 (find-class ',class)))
223 (defun keyslots-for-class (class)
224 (slot-value class 'key-slots))