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PHP Manual

# mysqli::select_db

# mysqli_select_db

Selects the default database for database queries

### Description

Object oriented style

bool mysqli::select_db ( string `$dbname` )

Procedural style

bool mysqli_select_db ( mysqli `$link` , string `$dbname` )

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.

### Parameters

`link`

  Procedural style only: A link identifier returned by mysqli_connect or mysqli_init

`dbname`

  The database name.

### Return Values

Returns `TRUE` on success or `FALSE` on failure.

### Examples

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.

### See Also

- mysqli_connect
- mysqli_real_connect