+;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10 -*-
+;;;; ======================================================================
+;;;; File: classes.lisp
+;;;; Updated: <04/04/2004 12:08:49 marcusp>
+;;;; ======================================================================
+;;;;
+;;;; Description ==========================================================
+;;;; ======================================================================
+;;;;
+;;;; Classes defining SQL expressions and methods for formatting the
+;;;; appropriate SQL commands.
+;;;;
+;;;; ======================================================================
+
+(in-package :clsql-usql-sys)
+
+
+(defvar *default-database* nil
+ "Specifies the default database to be used.")
+
+(defvar +empty-string+ "''")
+
+(defvar +null-string+ "NULL")
+
+(defvar *sql-stream* nil
+ "stream which accumulates SQL output")
+
+(defvar *default-schema* "UNCOMMONSQL")
+
+(defvar *object-schemas* (make-hash-table :test #'equal)
+ "Hash of schema name to class constituent lists.")
+
+(defun in-schema (schemaname)
+ (setf *default-schema* schemaname))
+
+(defun sql-output (sql-expr &optional database)
+ (progv '(*sql-stream*)
+ `(,(make-string-output-stream))
+ (output-sql sql-expr database)
+ (get-output-stream-string *sql-stream*)))
+
+
+(defclass %sql-expression ()
+ ())
+
+(defmethod output-sql ((expr %sql-expression) &optional
+ (database *default-database*))
+ (declare (ignore database))
+ (write-string +null-string+ *sql-stream*))
+
+(defmethod print-object ((self %sql-expression) stream)
+ (print-unreadable-object
+ (self stream :type t)
+ (write-string (sql-output self) stream)))
+
+;; For straight up strings
+
+(defclass sql (%sql-expression)
+ ((text
+ :initarg :string
+ :initform ""))
+ (:documentation "A literal SQL expression."))
+
+(defmethod make-load-form ((sql sql) &optional environment)
+ (declare (ignore environment))
+ (with-slots (text)
+ sql
+ `(make-instance 'sql :string ',text)))
+
+(defmethod output-sql ((expr sql) &optional (database *default-database*))
+ (declare (ignore database))
+ (write-string (slot-value expr 'text) *sql-stream*)
+ t)
+
+(defmethod print-object ((ident sql) stream)
+ (format stream "#<~S \"~A\">"
+ (type-of ident)
+ (sql-output ident)))
+
+;; For SQL Identifiers of generic type
+(defclass sql-ident (%sql-expression)
+ ((name
+ :initarg :name
+ :initform "NULL"))
+ (:documentation "An SQL identifer."))
+
+(defmethod make-load-form ((sql sql-ident) &optional environment)
+ (declare (ignore environment))
+ (with-slots (name)
+ sql
+ `(make-instance 'sql-ident :name ',name)))
+
+(defvar *output-hash* (make-hash-table :test #'equal))
+
+(defmethod output-sql-hash-key (expr &optional (database *default-database*))
+ (declare (ignore expr database))
+ nil)
+
+(defmethod output-sql :around ((sql t) &optional (database *default-database*))
+ (declare (ignore database))
+ (let* ((hash-key (output-sql-hash-key sql))
+ (hash-value (when hash-key (gethash hash-key *output-hash*))))
+ (cond ((and hash-key hash-value)
+ (write-string hash-value *sql-stream*))
+ (hash-key
+ (let ((*sql-stream* (make-string-output-stream)))
+ (call-next-method)
+ (setf hash-value (get-output-stream-string *sql-stream*))
+ (setf (gethash hash-key *output-hash*) hash-value))
+ (write-string hash-value *sql-stream*))
+ (t
+ (call-next-method)))))
+
+(defmethod output-sql ((expr sql-ident) &optional
+ (database *default-database*))
+ (declare (ignore database))
+ (with-slots (name)
+ expr
+ (etypecase name
+ (string
+ (write-string name *sql-stream*))
+ (symbol
+ (write-string (symbol-name name) *sql-stream*)))
+ t))
+
+;; For SQL Identifiers for attributes
+
+(defclass sql-ident-attribute (sql-ident)
+ ((qualifier
+ :initarg :qualifier
+ :initform "NULL")
+ (type
+ :initarg :type
+ :initform "NULL")
+ (params
+ :initarg :params
+ :initform nil))
+ (:documentation "An SQL Attribute identifier."))
+
+(defmethod collect-table-refs (sql)
+ (declare (ignore sql))
+ nil)
+
+(defmethod collect-table-refs ((sql sql-ident-attribute))
+ (let ((qual (slot-value sql 'qualifier)))
+ (if (and qual (symbolp (slot-value sql 'qualifier)))
+ (list (make-instance 'sql-ident-table :name
+ (slot-value sql 'qualifier))))))
+
+(defmethod make-load-form ((sql sql-ident-attribute) &optional environment)
+ (declare (ignore environment))
+ (with-slots (qualifier type name)
+ sql
+ `(make-instance 'sql-ident-attribute :name ',name
+ :qualifier ',qualifier
+ :type ',type)))
+
+(defmethod output-sql ((expr sql-ident-attribute) &optional
+ (database *default-database*))
+ (declare (ignore database))
+ (with-slots (qualifier name type params)
+ expr
+ (if (and name (not qualifier) (not type))
+ (write-string (sql-escape (symbol-name name)) *sql-stream*)
+ (format *sql-stream* "~@[~A.~]~A~@[ ~A~]"
+ (if qualifier (sql-escape qualifier) qualifier)
+ (sql-escape name)
+ type))
+ t))
+
+(defmethod output-sql-hash-key ((expr sql-ident-attribute) &optional
+ (database *default-database*))
+ (declare (ignore database))
+ (with-slots (qualifier name type params)
+ expr
+ (list 'sql-ident-attribute qualifier name type params)))
+
+;; For SQL Identifiers for tables
+(defclass sql-ident-table (sql-ident)
+ ((alias
+ :initarg :table-alias :initform nil))
+ (:documentation "An SQL table identifier."))
+
+(defmethod make-load-form ((sql sql-ident-table) &optional environment)
+ (declare (ignore environment))
+ (with-slots (alias name)
+ sql
+ `(make-instance 'sql-ident-table :name name :alias ',alias)))
+
+(defun generate-sql (expr)
+ (let ((*sql-stream* (make-string-output-stream)))
+ (output-sql expr)
+ (get-output-stream-string *sql-stream*)))
+
+(defmethod output-sql ((expr sql-ident-table) &optional
+ (database *default-database*))
+ (declare (ignore database))
+ (with-slots (name alias)
+ expr
+ (if (null alias)
+ (write-string (sql-escape (symbol-name name)) *sql-stream*)
+ (progn
+ (write-string (sql-escape (symbol-name name)) *sql-stream*)
+ (write-char #\Space *sql-stream*)
+ (format *sql-stream* "~s" alias))))
+ t)
+
+(defmethod output-sql-hash-key ((expr sql-ident-table) &optional
+ (database *default-database*))
+ (declare (ignore database))
+ (with-slots (name alias)
+ expr
+ (list 'sql-ident-table name alias)))
+
+(defclass sql-relational-exp (%sql-expression)
+ ((operator
+ :initarg :operator
+ :initform nil)
+ (sub-expressions
+ :initarg :sub-expressions
+ :initform nil))
+ (:documentation "An SQL relational expression."))
+
+(defmethod collect-table-refs ((sql sql-relational-exp))
+ (let ((tabs nil))
+ (dolist (exp (slot-value sql 'sub-expressions))
+ (let ((refs (collect-table-refs exp)))
+ (if refs (setf tabs (append refs tabs)))))
+ (remove-duplicates tabs
+ :test (lambda (tab1 tab2)
+ (equal (slot-value tab1 'name)
+ (slot-value tab2 'name))))))
+
+
+
+
+;; Write SQL for relational operators (like 'AND' and 'OR').
+;; should do arity checking of subexpressions
+
+(defmethod output-sql ((expr sql-relational-exp) &optional
+ (database *default-database*))
+ (with-slots (operator sub-expressions)
+ expr
+ (let ((subs (if (consp (car sub-expressions))
+ (car sub-expressions)
+ sub-expressions)))
+ (write-char #\( *sql-stream*)
+ (do ((sub subs (cdr sub)))
+ ((null (cdr sub)) (output-sql (car sub) database))
+ (output-sql (car sub) database)
+ (write-char #\Space *sql-stream*)
+ (output-sql operator database)
+ (write-char #\Space *sql-stream*))
+ (write-char #\) *sql-stream*)))
+ t)
+
+(defclass sql-upcase-like (sql-relational-exp)
+ ()
+ (:documentation "An SQL 'like' that upcases its arguments."))
+
+;; Write SQL for relational operators (like 'AND' and 'OR').
+;; should do arity checking of subexpressions
+
+(defmethod output-sql ((expr sql-upcase-like) &optional
+ (database *default-database*))
+ (flet ((write-term (term)
+ (write-string "upper(" *sql-stream*)
+ (output-sql term database)
+ (write-char #\) *sql-stream*)))
+ (with-slots (sub-expressions)
+ expr
+ (let ((subs (if (consp (car sub-expressions))
+ (car sub-expressions)
+ sub-expressions)))
+ (write-char #\( *sql-stream*)
+ (do ((sub subs (cdr sub)))
+ ((null (cdr sub)) (write-term (car sub)))
+ (write-term (car sub))
+ (write-string " LIKE " *sql-stream*))
+ (write-char #\) *sql-stream*))))
+ t)
+
+(defclass sql-assignment-exp (sql-relational-exp)
+ ()
+ (:documentation "An SQL Assignment expression."))
+
+
+(defmethod output-sql ((expr sql-assignment-exp) &optional
+ (database *default-database*))
+ (with-slots (operator sub-expressions)
+ expr
+ (do ((sub sub-expressions (cdr sub)))
+ ((null (cdr sub)) (output-sql (car sub) database))
+ (output-sql (car sub) database)
+ (write-char #\Space *sql-stream*)
+ (output-sql operator database)
+ (write-char #\Space *sql-stream*)))
+ t)
+
+(defclass sql-value-exp (%sql-expression)
+ ((modifier
+ :initarg :modifier
+ :initform nil)
+ (components
+ :initarg :components
+ :initform nil))
+ (:documentation
+ "An SQL value expression.")
+ )
+
+(defmethod collect-table-refs ((sql sql-value-exp))
+ (let ((tabs nil))
+ (if (listp (slot-value sql 'components))
+ (progn
+ (dolist (exp (slot-value sql 'components))
+ (let ((refs (collect-table-refs exp)))
+ (if refs (setf tabs (append refs tabs)))))
+ (remove-duplicates tabs
+ :test (lambda (tab1 tab2)
+ (equal (slot-value tab1 'name)
+ (slot-value tab2 'name)))))
+ nil)))
+
+
+
+(defmethod output-sql ((expr sql-value-exp) &optional
+ (database *default-database*))
+ (with-slots (modifier components)
+ expr
+ (if modifier
+ (progn
+ (write-char #\( *sql-stream*)
+ (output-sql modifier database)
+ (write-char #\Space *sql-stream*)
+ (output-sql components database)
+ (write-char #\) *sql-stream*))
+ (output-sql components database))))
+
+(defclass sql-typecast-exp (sql-value-exp)
+ ()
+ (:documentation "An SQL typecast expression."))
+
+(defmethod output-sql ((expr sql-typecast-exp) &optional
+ (database *default-database*))
+ (database-output-sql expr database))
+
+(defmethod database-output-sql ((expr sql-typecast-exp) database)
+ (with-slots (components)
+ expr
+ (output-sql components database)))
+
+
+(defmethod collect-table-refs ((sql sql-typecast-exp))
+ (when (slot-value sql 'components)
+ (collect-table-refs (slot-value sql 'components))))
+
+(defclass sql-function-exp (%sql-expression)
+ ((name
+ :initarg :name
+ :initform nil)
+ (args
+ :initarg :args
+ :initform nil))
+ (:documentation
+ "An SQL function expression."))
+
+(defmethod collect-table-refs ((sql sql-function-exp))
+ (let ((tabs nil))
+ (dolist (exp (slot-value sql 'components))
+ (let ((refs (collect-table-refs exp)))
+ (if refs (setf tabs (append refs tabs)))))
+ (remove-duplicates tabs
+ :test (lambda (tab1 tab2)
+ (equal (slot-value tab1 'name)
+ (slot-value tab2 'name))))))
+
+(defmethod output-sql ((expr sql-function-exp) &optional
+ (database *default-database*))
+ (with-slots (name args)
+ expr
+ (output-sql name database)
+ (when args (output-sql args database)))
+ t)
+
+(defclass sql-query (%sql-expression)
+ ((selections
+ :initarg :selections
+ :initform nil)
+ (all
+ :initarg :all
+ :initform nil)
+ (flatp
+ :initarg :flatp
+ :initform nil)
+ (set-operation
+ :initarg :set-operation
+ :initform nil)
+ (distinct
+ :initarg :distinct
+ :initform nil)
+ (from
+ :initarg :from
+ :initform nil)
+ (where
+ :initarg :where
+ :initform nil)
+ (group-by
+ :initarg :group-by
+ :initform nil)
+ (having
+ :initarg :having
+ :initform nil)
+ (limit
+ :initarg :limit
+ :initform nil)
+ (offset
+ :initarg :offset
+ :initform nil)
+ (order-by
+ :initarg :order-by
+ :initform nil)
+ (order-by-descending
+ :initarg :order-by-descending
+ :initform nil))
+ (:documentation "An SQL SELECT query."))
+
+(defmethod collect-table-refs ((sql sql-query))
+ (remove-duplicates (collect-table-refs (slot-value sql 'where))
+ :test (lambda (tab1 tab2)
+ (equal (slot-value tab1 'name)
+ (slot-value tab2 'name)))))
+
+(defvar *select-arguments*
+ '(:all :database :distinct :flatp :from :group-by :having :order-by
+ :order-by-descending :set-operation :where :offset :limit))
+
+(defun query-arg-p (sym)
+ (member sym *select-arguments*))
+
+(defun query-get-selections (select-args)
+ "Return two values: the list of select-args up to the first keyword,
+uninclusive, and the args from that keyword to the end."
+ (let ((first-key-arg (position-if #'query-arg-p select-args)))
+ (if first-key-arg
+ (values (subseq select-args 0 first-key-arg)
+ (subseq select-args first-key-arg))
+ select-args)))
+
+(defmethod make-query (&rest args)
+ (multiple-value-bind (selections arglist)
+ (query-get-selections args)
+ (destructuring-bind (&key all flatp set-operation distinct from where
+ group-by having order-by order-by-descending
+ offset limit &allow-other-keys)
+ arglist
+ (if (null selections)
+ (error "No target columns supplied to select statement."))
+ (if (null from)
+ (error "No source tables supplied to select statement."))
+ (make-instance 'sql-query :selections selections
+ :all all :flatp flatp :set-operation set-operation
+ :distinct distinct :from from :where where
+ :limit limit :offset offset
+ :group-by group-by :having having :order-by order-by
+ :order-by-descending order-by-descending))))
+
+(defvar *in-subselect* nil)
+
+(defmethod output-sql ((query sql-query) &optional
+ (database *default-database*))
+ (with-slots (distinct selections from where group-by having order-by
+ order-by-descending limit offset)
+ query
+ (when *in-subselect*
+ (write-string "(" *sql-stream*))
+ (write-string "SELECT " *sql-stream*)
+ (when distinct
+ (write-string "DISTINCT " *sql-stream*)
+ (unless (eql t distinct)
+ (write-string "ON " *sql-stream*)
+ (output-sql distinct database)
+ (write-char #\Space *sql-stream*)))
+ (output-sql (apply #'vector selections) database)
+ (write-string " FROM " *sql-stream*)
+ (if (listp from)
+ (output-sql (apply #'vector from) database)
+ (output-sql from database))
+ (when where
+ (write-string " WHERE " *sql-stream*)
+ (let ((*in-subselect* t))
+ (output-sql where database)))
+ (when group-by
+ (write-string " GROUP BY " *sql-stream*)
+ (output-sql group-by database))
+ (when having
+ (write-string " HAVING " *sql-stream*)
+ (output-sql having database))
+ (when order-by
+ (write-string " ORDER BY " *sql-stream*)
+ (if (listp order-by)
+ (do ((order order-by (cdr order)))
+ ((null order))
+ (output-sql (car order) database)
+ (when (cdr order)
+ (write-char #\, *sql-stream*)))
+ (output-sql order-by database)))
+ (when order-by-descending
+ (write-string " ORDER BY " *sql-stream*)
+ (if (listp order-by-descending)
+ (do ((order order-by-descending (cdr order)))
+ ((null order))
+ (output-sql (car order) database)
+ (when (cdr order)
+ (write-char #\, *sql-stream*)))
+ (output-sql order-by-descending database))
+ (write-string " DESC " *sql-stream*))
+ (when limit
+ (write-string " LIMIT " *sql-stream*)
+ (output-sql limit database))
+ (when offset
+ (write-string " OFFSET " *sql-stream*)
+ (output-sql offset database))
+ (when *in-subselect*
+ (write-string ")" *sql-stream*)))
+ t)
+
+;; INSERT
+
+(defclass sql-insert (%sql-expression)
+ ((into
+ :initarg :into
+ :initform nil)
+ (attributes
+ :initarg :attributes
+ :initform nil)
+ (values
+ :initarg :values
+ :initform nil)
+ (query
+ :initarg :query
+ :initform nil))
+ (:documentation
+ "An SQL INSERT statement."))
+
+(defmethod output-sql ((ins sql-insert) &optional
+ (database *default-database*))
+ (with-slots (into attributes values query)
+ ins
+ (write-string "INSERT INTO " *sql-stream*)
+ (output-sql into database)
+ (when attributes
+ (write-char #\Space *sql-stream*)
+ (output-sql attributes database))
+ (when values
+ (write-string " VALUES " *sql-stream*)
+ (output-sql values database))
+ (when query
+ (write-char #\Space *sql-stream*)
+ (output-sql query database)))
+ t)
+
+;; DELETE
+
+(defclass sql-delete (%sql-expression)
+ ((from
+ :initarg :from
+ :initform nil)
+ (where
+ :initarg :where
+ :initform nil))
+ (:documentation
+ "An SQL DELETE statement."))
+
+(defmethod output-sql ((stmt sql-delete) &optional
+ (database *default-database*))
+ (with-slots (from where)
+ stmt
+ (write-string "DELETE FROM " *sql-stream*)
+ (typecase from
+ (symbol (write-string (sql-escape from) *sql-stream*))
+ (t (output-sql from database)))
+ (when where
+ (write-string " WHERE " *sql-stream*)
+ (output-sql where database)))
+ t)
+
+;; UPDATE
+
+(defclass sql-update (%sql-expression)
+ ((table
+ :initarg :table
+ :initform nil)
+ (attributes
+ :initarg :attributes
+ :initform nil)
+ (values
+ :initarg :values
+ :initform nil)
+ (where
+ :initarg :where
+ :initform nil))
+ (:documentation "An SQL UPDATE statement."))
+
+(defmethod output-sql ((expr sql-update) &optional
+ (database *default-database*))
+ (with-slots (table where attributes values)
+ expr
+ (flet ((update-assignments ()
+ (mapcar #'(lambda (a b)
+ (make-instance 'sql-assignment-exp
+ :operator '=
+ :sub-expressions (list a b)))
+ attributes values)))
+ (write-string "UPDATE " *sql-stream*)
+ (output-sql table database)
+ (write-string " SET " *sql-stream*)
+ (output-sql (apply #'vector (update-assignments)) database)
+ (when where
+ (write-string " WHERE " *sql-stream*)
+ (output-sql where database))))
+ t)
+
+;; CREATE TABLE
+
+(defclass sql-create-table (%sql-expression)
+ ((name
+ :initarg :name
+ :initform nil)
+ (columns
+ :initarg :columns
+ :initform nil)
+ (modifiers
+ :initarg :modifiers
+ :initform nil))
+ (:documentation
+ "An SQL CREATE TABLE statement."))
+
+;; Here's a real warhorse of a function!
+
+(defun listify (x)
+ (if (atom x)
+ (list x)
+ x))
+
+(defmethod output-sql ((stmt sql-create-table) &optional
+ (database *default-database*))
+ (flet ((output-column (column-spec)
+ (destructuring-bind (name type &rest constraints)
+ column-spec
+ (let ((type (listify type)))
+ (output-sql name database)
+ (write-char #\Space *sql-stream*)
+ (write-string
+ (database-get-type-specifier (car type) (cdr type) database)
+ *sql-stream*)
+ (let ((constraints
+ (database-constraint-statement constraints database)))
+ (when constraints
+ (write-string " " *sql-stream*)
+ (write-string constraints *sql-stream*)))))))
+ (with-slots (name columns modifiers)
+ stmt
+ (write-string "CREATE TABLE " *sql-stream*)
+ (output-sql name database)
+ (write-string " (" *sql-stream*)
+ (do ((column columns (cdr column)))
+ ((null (cdr column))
+ (output-column (car column)))
+ (output-column (car column))
+ (write-string ", " *sql-stream*))
+ (when modifiers
+ (do ((modifier (listify modifiers) (cdr modifier)))
+ ((null modifier))
+ (write-string ", " *sql-stream*)
+ (write-string (car modifier) *sql-stream*)))
+ (write-char #\) *sql-stream*)))
+ t)
+
+
+;; CREATE VIEW
+
+(defclass sql-create-view (%sql-expression)
+ ((name :initarg :name :initform nil)
+ (column-list :initarg :column-list :initform nil)
+ (query :initarg :query :initform nil)
+ (with-check-option :initarg :with-check-option :initform nil))
+ (:documentation "An SQL CREATE VIEW statement."))
+
+(defmethod output-sql ((stmt sql-create-view) &optional database)
+ (with-slots (name column-list query with-check-option) stmt
+ (write-string "CREATE VIEW " *sql-stream*)
+ (output-sql name database)
+ (when column-list (write-string " " *sql-stream*)
+ (output-sql (listify column-list) database))
+ (write-string " AS " *sql-stream*)
+ (output-sql query database)
+ (when with-check-option (write-string " WITH CHECK OPTION" *sql-stream*))))
+
+
+;;
+;; Column constraint types
+;;
+(defparameter *constraint-types*
+ '(("NOT-NULL" . "NOT NULL")
+ ("PRIMARY-KEY" . "PRIMARY KEY")))
+
+;;
+;; Convert type spec to sql syntax
+;;
+
+(defmethod database-constraint-description (constraint database)
+ (declare (ignore database))
+ (let ((output (assoc (symbol-name constraint) *constraint-types*
+ :test #'equal)))
+ (if (null output)
+ (error 'clsql-sql-syntax-error
+ :reason (format nil "unsupported column constraint '~a'"
+ constraint))
+ (cdr output))))
+
+(defmethod database-constraint-statement (constraint-list database)
+ (declare (ignore database))
+ (make-constraints-description constraint-list))
+
+(defun make-constraints-description (constraint-list)
+ (if constraint-list
+ (let ((string ""))
+ (do ((constraint constraint-list (cdr constraint)))
+ ((null constraint) string)
+ (let ((output (assoc (symbol-name (car constraint))
+ *constraint-types*
+ :test #'equal)))
+ (if (null output)
+ (error 'clsql-sql-syntax-error
+ :reason (format nil "unsupported column constraint '~a'"
+ constraint))
+ (setq string (concatenate 'string string (cdr output))))
+ (if (< 1 (length constraint))
+ (setq string (concatenate 'string string " "))))))))
+