mysqli::begin_transaction

    mysqli_begin_transaction

    (PHP 5 >= 5.5.0, PHP 7, PHP 8)

    mysqli::begin_transaction -- mysqli_begin_transaction — Inicia una transacción

    Descripción

    Estilo orientado a objetos (método):

    public mysqli::begin_transaction(int $flags = ?, string $name = ?): bool

    Estilo por procedimientos:

    mysqli_begin_transaction(mysqli $link, int $flags = ?, string $name = ?): bool

    Comienza una transacción. Requiere MySQL 5.6 y superior, y el motor InnoDB (está habilitado por defecto). Para detalles adicionales sobre cómo funcionan las transacciones de MySQL, véase » http://dev.mysql.com/doc/mysql/en/commit.html.

    Parámetros

    link

    Sólo estilo por procediminetos: Un identificador de enlace devuelto por mysqli_connect() o mysqli_init()

    flags

    Banderas. Las válidas son:

    • MYSQLI_TRANS_START_READ_ONLY: Inicia la transacción como "START TRANSACTION READ ONLY".

    • MYSQLI_TRANS_START_READ_WRITE: Inicia la transacción como "START TRANSACTION READ WRITE".

    • MYSQLI_TRANS_START_WITH_CONSISTENT_SNAPSHOT: Inicia la transacción como "START TRANSACTION WITH CONSISTENT SNAPSHOT".

    name

    Nombre del punto de prevención de la transacción.

    Valores devueltos

    Devuelve true en caso de éxito o false en caso de error.

    Ejemplos

    Ejemplo #1 Ejemplo de $mysqli->begin_transaction()

    Estilo orientado a objetos

    <?php
    $mysqli     = new mysqli("127.0.0.1", "mi_usuario", "mi_contraseña", "sakila");

    if (    $mysqli->connect_errno) {
    printf("Conexión fallida: %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();
    ?>

    Estilo por procedimientos

    <?php
    $enlace     = mysqli_connect("127.0.0.1", "mi_usuario", "mi_contraseña", "sakila");

    if (    mysqli_connect_errno()) {
    printf("Conexión fallida: %s\n", mysqli_connect_error());
    exit();
    }

    mysqli_begin_transaction($enlace, MYSQLI_TRANS_START_READ_ONLY);

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

    mysqli_close($enlace);
    ?>

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    User Contributed Notes 4 notes

    up
    8
    Ral
    6 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.
    up
    2
    PHP Guru
    4 years 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
    5 years 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
    -2
    Luc
    8 years ago
    For PHP<5.5:

    mysqli_query($db, "START TRANSACTION");
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