db2_rollback

(no version information, might be only in CVS)

db2_rollback --  Rolls back a transaction

説明

bool db2_rollback ( resource connection )

警告

この関数は、 実験的なステータスにあります。これは、この関数の 動作、関数名、ここで書かれていること全てがPHPの将来のバージョンで予告 なく変更される可能性があることを意味します。注意を喚起するとともに自分 のリスクでこの関数を使用してください。

Rolls back an in-progress transaction on the specified connection resource and begins a new transaction. PHP applications normally default to AUTOCOMMIT mode, so db2_rollback() normally has no effect unless AUTOCOMMIT has been turned off for the connection resource.

注意: If the specified connection resource is a persistent connection, all transactions in progress for all applications using that persistent connection will be rolled back. For this reason, persistent connections are not recommended for use in applications that require transactions.

パラメータ

connection

A valid database connection resource variable as returned from db2_connect() or db2_pconnect().

戻り値

成功した場合に TRUE を、失敗した場合に FALSE を返します。

例 1. Rolling back a DELETE statement

In the following example, we count the number of rows in a table, turn off AUTOCOMMIT mode on a database connection, delete all of the rows in the table and return the count of 0 to prove that the rows have been removed. We then issue db2_rollback() and return the updated count of rows in the table to show that the number is the same as before we issued the DELETE statement. The return to the original state of the table demonstrates that the roll back of the transaction succeeded.

<?php
$conn
= db2_connect($database, $user, $password);

if (
$conn) {
    
$stmt = db2_exec($conn, "SELECT count(*) FROM animals");
    
$res = db2_fetch_array( $stmt );
    echo
$res[0] . "\n";
    
    
// Turn AUTOCOMMIT off
    
db2_autocommit($conn, DB2_AUTOCOMMIT_OFF);
   
    
// Delete all rows from ANIMALS
    
db2_exec($conn, "DELETE FROM animals");
    
    
$stmt = db2_exec($conn, "SELECT count(*) FROM animals");
    
$res = db2_fetch_array( $stmt );
    echo
$res[0] . "\n";
    
    
// Roll back the DELETE statement
    
db2_rollback( $conn );
    
    
$stmt = db2_exec( $conn, "SELECT count(*) FROM animals" );
    
$res = db2_fetch_array( $stmt );
    echo
$res[0] . "\n";
    
db2_close($conn);
}
?>

上の例の出力は以下となります:

7
0
7

以下も参照ください

db2_autocommit()
db2_commit()