;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10 -*-
;;;; *************************************************************************
;;;;
-;;;; $Id$
-;;;;
;;;; Transaction support
;;;;
;;;; This file is part of CLSQL.
(defclass transaction ()
((commit-hooks :initform () :accessor commit-hooks)
(rollback-hooks :initform () :accessor rollback-hooks)
- (status :initform nil :accessor transaction-status))) ; nil or :committed
-
-(defun commit-transaction (database)
- (when (and (transaction database)
- (not (transaction-status (transaction database))))
- (setf (transaction-status (transaction database)) :committed)))
+ (previous-autocommit :initarg :previous-autocommit
+ :reader previous-autocommit)
+ (status :initform nil :accessor transaction-status
+ :documentation "nil or :committed")))
-(defun add-transaction-commit-hook (database commit-hook)
+(defun add-transaction-commit-hook (commit-hook &key
+ (database *default-database*))
+ "Adds COMMIT-HOOK, which should a designator for a function
+with no required arguments, to the list of hooks run when COMMIT
+is called on DATABASE which defaults to *DEFAULT-DATABASE*."
(when (transaction database)
(push commit-hook (commit-hooks (transaction database)))))
-(defun add-transaction-rollback-hook (database rollback-hook)
+(defun add-transaction-rollback-hook (rollback-hook
+ &key (database *default-database*))
+ "Adds ROLLBACK-HOOK, which should a designator for a function
+with no required arguments, to the list of hooks run when ROLLBACK
+is called on DATABASE which defaults to *DEFAULT-DATABASE*."
(when (transaction database)
(push rollback-hook (rollback-hooks (transaction database)))))
(defmethod database-start-transaction ((database database))
(unless (transaction database)
- (setf (transaction database) (make-instance 'transaction)))
- (when (= (incf (transaction-level database) 1))
+ (setf (transaction database)
+ (make-instance 'transaction :previous-autocommit
+ (database-autocommit database))))
+ (setf (database-autocommit database) nil)
+ (when (= (incf (transaction-level database)) 1)
(let ((transaction (transaction database)))
(setf (commit-hooks transaction) nil
(rollback-hooks transaction) nil
(transaction-status transaction) nil)
- (execute-command "BEGIN" :database database))))
+ (case (database-underlying-type database)
+ (:oracle nil)
+ (:mssql (execute-command "BEGIN TRANSACTION" :database database))
+ (t (execute-command "BEGIN" :database database))))))
+;;ODBC should potentially be using it's scheme for transactions:
+;; turn off autocommit for begin. then use sqlendtran (or maybe sqltransact)
+;; whatever is appropriate for this version of odbc.
(defmethod database-commit-transaction ((database database))
- (if (> (transaction-level database) 0)
- (when (zerop (decf (transaction-level database)))
- (execute-command "COMMIT" :database database)
- (map nil #'funcall (commit-hooks (transaction database))))
- (warn 'clsql-simple-warning
- :format-control "Cannot commit transaction against ~A because there is no transaction in progress."
- :format-arguments (list database))))
+ (with-slots (transaction transaction-level autocommit) database
+ (if (plusp transaction-level)
+ (if (zerop (decf transaction-level))
+ (progn
+ (case (database-underlying-type database)
+ (:mssql (execute-command "COMMIT TRANSACTION" :database database))
+ (t (execute-command "COMMIT" :database database)))
+ (setf autocommit (previous-autocommit transaction))
+ (map nil #'funcall (commit-hooks transaction)))
+ (setf (transaction-status (transaction database)) nil))
+ (warn 'sql-warning
+ :message
+ (format nil "Cannot commit transaction against ~A because there is no transaction in progress."
+ database)))))
-(defmethod database-abort-transaction (database)
- (if (> (transaction-level database) 0)
- (when (zerop (decf (transaction-level database)))
- (unwind-protect
- (execute-command "ROLLBACK" :database database)
- (map nil #'funcall (rollback-hooks (transaction database)))))
- (warn 'clsql-simple-warning
- :format-control "Cannot abort transaction against ~A because there is no transaction in progress."
- :format-arguments (list database))))
+(defmethod database-abort-transaction ((database database))
+ (with-slots (transaction transaction-level autocommit) database
+ (if (plusp transaction-level)
+ (when (zerop (decf transaction-level))
+ (unwind-protect
+ (case (database-underlying-type database)
+ (:mssql (execute-command "ROLLBACK TRANSACTION" :database database))
+ (t (execute-command "ROLLBACK" :database database)))
+ (setf autocommit (previous-autocommit transaction))
+ (map nil #'funcall (rollback-hooks transaction))))
+ (warn 'sql-warning
+ :message
+ (format nil "Cannot abort transaction against ~A because there is no transaction in progress."
+ database)))))
+(defun mark-transaction-committed (database)
+ (when (and (transaction database)
+ (not (transaction-status (transaction database))))
+ (setf (transaction-status (transaction database)) :committed)))
(defmacro with-transaction ((&key (database '*default-database*)) &rest body)
"Starts a transaction in the database specified by DATABASE,
(let ((db (gensym "db-")))
`(let ((,db ,database))
(unwind-protect
- (progn
+ (prog2
(database-start-transaction ,db)
- ,@body
- (commit-transaction ,db))
+ (progn
+ ,@body)
+ (mark-transaction-committed ,db))
(if (eq (transaction-status (transaction ,db)) :committed)
(database-commit-transaction ,db)
(database-abort-transaction ,db))))))
"If DATABASE, which defaults to *DEFAULT-DATABASE*, is
currently within the scope of a transaction, commits changes made
since the transaction began."
- (database-commit-transaction database))
+ (database-commit-transaction database)
+ nil)
(defun rollback (&key (database *default-database*))
"If DATABASE, which defaults to *DEFAULT-DATABASE*, is
currently within the scope of a transaction, rolls back changes
made since the transaction began."
- (database-abort-transaction database))
+ (database-abort-transaction database)
+ nil)
(defun start-transaction (&key (database *default-database*))
"Starts a transaction block on DATABASE which defaults to
*DEFAULT-DATABASE* and which continues until ROLLBACK or COMMIT
are called."
(unless (in-transaction-p :database database)
- (database-start-transaction database)))
+ (database-start-transaction database))
+ nil)
(defun in-transaction-p (&key (database *default-database*))
"A predicate to test whether DATABASE, which defaults to
*DEFAULT-DATABASE*, is currently within the scope of a
transaction."
(and database (transaction database) (= (transaction-level database) 1)))
+
+(defun set-autocommit (value &key (database *default-database*))
+ "Turns autocommit off for DATABASE if VALUE is NIL, and
+otherwise turns it on. Returns the old value of autocommit flag.
+For RDBMS (such as Oracle) which don't automatically commit
+changes, turning autocommit on has the effect of explicitly
+committing changes made whenever SQL statements are executed.
+Autocommit is turned on by default."
+ (let ((old-value (database-autocommit database)))
+ (setf (database-autocommit database) value)
+ (database-autocommit database)
+ old-value))
+