X-Git-Url: http://git.kpe.io/?p=clsql.git;a=blobdiff_plain;f=sql%2Fsequences.lisp;fp=sql%2Fsequences.lisp;h=1e3ef9ec6b75475848c320c5daf6c09662c4473f;hp=0000000000000000000000000000000000000000;hb=5148be446aee32ec705beac3fbba35f499df4fd4;hpb=bb2818fb8a6714a55b360dec0bb043c5edccb3f4

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+;;;; -*- 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))))