mysqli::select_db

mysqli_select_db

Selects the default database for database queries

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&style.oop;

`bool` `mysqli::select_db` `string` `dbname`

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`bool` `mysqli_select_db` `mysqli` `link` `string` `dbname`

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

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`.

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&mysqli.link.description;

`dbname`

- The database name.

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&return.success;

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### `mysqli::select_db` example

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    <?php
    $mysqli = new mysqli("localhost", "my_user", "my_password", "test");

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

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

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

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

    $mysqli->close();
    ?>

&style.procedural;

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

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

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

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

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

    mysqli_close($link);
    ?>

&examples.outputs;

    Default database is test.
    Default database is world.

&reftitle.seealso;

- `mysqli_connect`
- `mysqli_real_connect`