mysqli::select_db
PHP function
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(PHP 5, PHP 7, PHP 8)
Selects the default database for database queries
Description
Oop
mysqli::select_db(string $database): bool
Procedural
mysqli_select_db(mysqli $mysql, string $database): 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 the 4th parameter in mysqli_connect().
Parameters
databaseThe database name.
Return Values
Success
Errors/Exceptions Conditionalexception
Examples
mysqli::select_db example
Oop
php
<?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]);Procedural
php
<?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]);Outputs
output
Default database is test.
Default database is world.