(PHP 5, PHP 7)
mysqli::select_db -- mysqli_select_db — Selects the default database for database queries
Object oriented style
public mysqli::select_db ( string $dbname ) : bool
Procedural style
mysqli_select_db ( mysqli $link , string $dbname ) : bool
Selects the default database to be used when performing queries against the database connection.
Note:
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().
link
Procedural style only: A link identifier returned by mysqli_connect() or mysqli_init()
dbname
The database name.
Returns true
on success or false
on failure.
Example #1 mysqli::select_db() example
Object oriented style
<?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(); ?>
Procedural style
<?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); ?>
The above examples will output:
Default database is test. Default database is world.
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https://www.php.net/manual/en/mysqli.select-db.php