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    mysqli::select_db

    mysqli_select_db

    (PHP 5, PHP 7, PHP 8)

    mysqli::select_db -- mysqli_select_db — Selects the default database for database queries

    Descrizione

    Stile orientato agli oggetti

    public mysqli::select_db(string $database): bool

    Stile procedurale

    mysqli_select_db(mysqli $mysql, string $database): bool

    Selects the default database to be used when performing queries against the database connection.

    Nota:

    This function should only be used to change the default database for the connection. You can select the default database with 4th parameter in mysqli_connect().

    Elenco dei parametri

    link

    Solo nello stile procedurale: un identificatore restituito da mysqli_connect() o mysqli_init()

    database

    The database name.

    Valori restituiti

    Restituisce true in caso di successo, false in caso di fallimento.

    Errori/Eccezioni

    If mysqli error reporting is enabled (MYSQLI_REPORT_ERROR) and the requested operation fails, a warning is generated. If, in addition, the mode is set to MYSQLI_REPORT_STRICT, a mysqli_sql_exception is thrown instead.

    Esempi

    Example #1 mysqli::select_db() example

    Stile orientato agli oggetti

    <?php

    mysqli_report    (MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
    $mysqli = new mysqli("localhost", "my_user", "my_password", "test");

    /* get the name of the current default database */
    $result = $mysqli->query("SELECT DATABASE()");
    $row = $result->fetch_row();
    printf("Default database is %s.\n", $row[0]);

    /* change default database to "world" */
    $mysqli->select_db("world");

    /* get the name of the current default database */
    $result = $mysqli->query("SELECT DATABASE()");
    $row = $result->fetch_row();
    printf("Default database is %s.\n", $row[0]);

    Stile procedurale

    <?php

    mysqli_report    (MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
    $link = mysqli_connect("localhost", "my_user", "my_password", "test");

    /* get the name of the current default database */
    $result = mysqli_query($link, "SELECT DATABASE()");
    $row = mysqli_fetch_row($result);
    printf("Default database is %s.\n", $row[0]);

    /* change default database to "world" */
    mysqli_select_db($link, "world");

    /* get the name of the current default database */
    $result = mysqli_query($link, "SELECT DATABASE()");
    $row = mysqli_fetch_row($result);
    printf("Default database is %s.\n", $row[0]);

    I precedenti esempi visualizzeranno:

    Default database is test.
Default database is world.

    Vedere anche:

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    User Contributed Notes 1 note

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    lori at astoundingteam dot com
    1 year ago
    Note that the order of arguments for `mysqli_select_db` is opposite what it is for the deprecated `mysql_select_db`.
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