mysqli::begin_transaction

mysqli_begin_transaction

(PHP 5 >= 5.5.0, PHP 7)

mysqli::begin_transaction -- mysqli_begin_transactionStarts a transaction

Description

Object oriented style

public mysqli::begin_transaction ([ int $flags = 0 [, string $name ]] ) : bool

Procedural style:

mysqli_begin_transaction ( mysqli $link [, int $flags = 0 [, string $name ]] ) : bool

Begins a transaction. Requires the InnoDB engine (it is enabled by default). For additional details about how MySQL transactions work, see » http://dev.mysql.com/doc/mysql/en/commit.html.

Parameters

link

Procedural style only: A link identifier returned by mysqli_connect() or mysqli_init()

flags

Valid flags are:

  • MYSQLI_TRANS_START_READ_ONLY: Start the transaction as "START TRANSACTION READ ONLY". Requires MySQL 5.6 and above.

  • MYSQLI_TRANS_START_READ_WRITE: Start the transaction as "START TRANSACTION READ WRITE". Requires MySQL 5.6 and above.

  • MYSQLI_TRANS_START_WITH_CONSISTENT_SNAPSHOT: Start the transaction as "START TRANSACTION WITH CONSISTENT SNAPSHOT".

name

Savepoint name for the transaction.

Return Values

Returns TRUE on success or FALSE on failure.

Examples

Example #1 $mysqli->begin_transaction() example

Object oriented style

<?php
$mysqli 
= new mysqli("127.0.0.1""my_user""my_password""sakila");

if (
$mysqli->connect_errno) {
    
printf("Connect failed: %s\n"$mysqli->connect_error);
    exit();
}

$mysqli->begin_transaction(MYSQLI_TRANS_START_READ_ONLY);

$mysqli->query("SELECT first_name, last_name FROM actor");
$mysqli->commit();

$mysqli->close();
?>

Procedural style

<?php
$link 
mysqli_connect("127.0.0.1""my_user""my_password""sakila");

if (
mysqli_connect_errno()) {
    
printf("Connect failed: %s\n"mysqli_connect_error());
    exit();
}

mysqli_begin_transaction($linkMYSQLI_TRANS_START_READ_ONLY);

mysqli_query($link"SELECT first_name, last_name FROM actor LIMIT 1");
mysqli_commit($link);

mysqli_close($link);
?>

See Also

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User Contributed Notes 4 notes

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5
Ral
2 years ago
If you receive errors like: "This server version doesn't support 'READ WRITE' and 'READ ONLY'. Minimum 5.6.5 is required" with versions of MariaDB that DO support them, this is due to an internal check in mysqli conflicting with a hack in MariaDB to allow replication with oracle mysql.

MariaDB prefixes its server version numbers with "5.5.5-" for example "5.5.5-10.3.7-MariaDB-1:10.3.7+maria~stretch". This is because oracle mysql would interpet the "10" as version 1. Mysql clients aware of MariaDB have been updated to detect and strip this prefix.

However the check for mysqli.begin-transaction sees the 5.5.5 prefix and so fails.

The workaround is to specify a custom version string without the prefix for MariaDB on the command line using the --version option. Then mysqli.begin-transaction functions as expected.
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1
PHP Guru
4 months ago
MySQL 5.6 introduces READ ONLY mode which applies optimizations to your transactions that can only be applied when it knows in advance that no table modifications will be made and that no locks will be issued.

The default access mode is READ WRITE in all versions up to and including MySQL 5.6. Starting in MySQL 5.7, the appropriate access mode is detected automatically. So if your transaction attempts modifications or table locks, it will automatically use READ WRITE mode, otherwise it will use READ ONLY mode and your transaction will benefit from the optimizations that come from that without having to explicitly declare is as READ ONLY.

Therefore the only time you need to explicitly declare an access mode is when you are using MySQL 5.6 and you are sure that you want READ ONLY mode. Note that any queries that attempt to modify tables or issue locks in READ ONLY mode will fail. Temporary tables can still be modified.

(Moderators. This post should replace the previous post that I made on the subject. Thanks.)
up
1
VasK@hapir
1 year ago
The above answer from Ral worked for us, Thanks a lot. This is how we implemented the proposed workaround for

Warning: mysqli_begin_transaction(): This server version doesn't support 'READ WRITE' and 'READ ONLY'. Minimum 5.6.5 is required

We appended the following line to /etc/my.cnf and restarted MySQL server

version=10.2.19-MariaDB
up
-1
Luc
3 years ago
For PHP<5.5:

    mysqli_query($db, "START TRANSACTION");
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