PHP & mySQL: Simple code to implement Transaction - Commit & Rollback

MY PLATFORM:

PHP & mySQL

MY SITUATION:

I am trying to implement transactions within my code. I tried to follow examples, but it's not much help. I am running 3 queries and I wanted to write a transaction in such a way so that if any of the query(ies) fail, the whole transaction should roll back. I would really appreciate a simple, efficient and non-object oriented PHP code to achieve this goal. Thank you in advance.

MY PHP CODE:

//db_res call开发者_StackOverflow社区s a custom function that performs a mysql_query on the query
$res1 = db_res("SELECT c1, c2 FROM t1 WHERE c5 = 3");
$res2 = db_res("UPDATE t2 SET c1 = 5 WHERE c2 = 10");
$res3 = db_res("DELETE FROM t3 WHERE c1 = 20");

if( $res1 && $res2 && $res3 )
{
 //commit --- but how?
}
else
{
 //rollback --- but how?
}

You don't need to use mysqli. You can just issue the transaction commands as queries.

So for your example:

mysql_query("start transaction;");

//db_res calls a custom function that performs a mysql_query on the query
$res1 = db_res("SELECT c1, c2 FROM t1 WHERE c5 = 3");
$res2 = db_res("UPDATE t2 SET c1 = 5 WHERE c2 = 10");
$res3 = db_res("DELETE FROM t3 WHERE c1 = 20");

if( $res1 && $res2 && $res3 )
{
  mysql_query("commit;");
}
else
{
  mysql_query("rollback;");
}

By they way if you are thinking about upgrading to mysqli, please don't. Upgrade to PDO instead, it's much more sane.

You need to use the mysqli extension to use this functionality.

See: autocommit(), commit(), and rollback()

<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

/* disable autocommit */
mysqli_autocommit($link, FALSE);

mysqli_query($link, "CREATE TABLE myCity LIKE City");
mysqli_query($link, "ALTER TABLE myCity Type=InnoDB");
mysqli_query($link, "INSERT INTO myCity SELECT * FROM City LIMIT 50");

/* commit insert */
mysqli_commit($link);

/* delete all rows */
mysqli_query($link, "DELETE FROM myCity");

if ($result = mysqli_query($link, "SELECT COUNT(*) FROM myCity")) {
    $row = mysqli_fetch_row($result);
    printf("%d rows in table myCity.\n", $row[0]);
    /* Free result */
    mysqli_free_result($result);
}

/* Rollback */
mysqli_rollback($link);

if ($result = mysqli_query($link, "SELECT COUNT(*) FROM myCity")) {
    $row = mysqli_fetch_row($result);
    printf("%d rows in table myCity (after rollback).\n", $row[0]);
    /* Free result */
    mysqli_free_result($result);
}

/* Drop table myCity */
mysqli_query($link, "DROP TABLE myCity");

mysqli_close($link);
?>