--- /dev/null
+;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10 -*-
+;;;; *************************************************************************
+;;;;
+;;;; $Id:$
+;;;;
+;;;; Generic sequence implementation. Backends should use native sequences if
+;;;; are available.
+;;;;
+;;;; This file is part of CLSQL.
+;;;;
+;;;; CLSQL users are granted the rights to distribute and use this software
+;;;; as governed by the terms of the Lisp Lesser GNU Public License
+;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
+;;;; *************************************************************************
+
+(in-package #:clsql-sys)
+
+(defclass generic-database (database)
+ ()
+ (:documentation "Encapsulate same behavior across backends."))
+
+
+;;; Sequence functions
+
+(defun %sequence-name-to-table (sequence-name database)
+ (concatenate 'string
+ (convert-to-db-default-case "_CLSQL_SEQ_" database)
+ (sql-escape sequence-name)))
+
+(defun %table-name-to-sequence-name (table-name database)
+ (and (>= (length table-name) 11)
+ (string-equal (subseq table-name 0 11)
+ (convert-to-db-default-case "_CLSQL_SEQ_" database))
+ (subseq table-name 11)))
+
+(defmethod database-create-sequence (sequence-name database)
+ (let ((table-name (%sequence-name-to-table sequence-name database)))
+ (database-execute-command
+ (concatenate 'string "CREATE TABLE " table-name
+ " (last_value int NOT NULL PRIMARY KEY, increment_by int, min_value int, is_called char(1))")
+ database)
+ (database-execute-command
+ (concatenate 'string "INSERT INTO " table-name
+ " VALUES (1,1,1,'f')")
+ database)))
+
+(defmethod database-drop-sequence (sequence-name database)
+ (database-execute-command
+ (concatenate 'string "DROP TABLE " (%sequence-name-to-table sequence-name database))
+ database))
+
+(defmethod database-list-sequences (database &key (owner nil))
+ (declare (ignore owner))
+ (mapcan #'(lambda (s)
+ (let ((sn (%table-name-to-sequence-name s database)))
+ (and sn (list sn))))
+ (database-list-tables-and-sequences database)))
+
+(defmethod database-set-sequence-position (sequence-name (position integer) database)
+ (database-execute-command
+ (format nil "UPDATE ~A SET last_value=~A,is_called='t'"
+ (%sequence-name-to-table sequence-name database)
+ position)
+ database)
+ position)
+
+(defmethod database-sequence-next (sequence-name database)
+ (without-interrupts
+ (let* ((table-name (%sequence-name-to-table sequence-name database))
+ (tuple
+ (car (database-query
+ (concatenate 'string "SELECT last_value,is_called FROM "
+ table-name)
+ database :auto nil))))
+ (cond
+ ((char-equal (schar (second tuple) 0) #\f)
+ (database-execute-command
+ (format nil "UPDATE ~A SET is_called='t'" table-name)
+ database)
+ (car tuple))
+ (t
+ (let ((new-pos (1+ (car tuple))))
+ (database-execute-command
+ (format nil "UPDATE ~A SET last_value=~D" table-name new-pos)
+ database)
+ new-pos))))))
+
+(defmethod database-sequence-last (sequence-name database)
+ (without-interrupts
+ (caar (database-query
+ (concatenate 'string "SELECT last_value FROM "
+ (%sequence-name-to-table sequence-name database))
+ database :auto nil))))