PHP 8.0.26 Released!

mysqli::select_db

mysqli_select_db

(PHP 5, PHP 7, PHP 8)

mysqli::select_db -- mysqli_select_dbSelects the default database for database queries

Description

Object-oriented style

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

Procedural style

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 4th parameter in mysqli_connect().

Parameters

mysql

Procedural style only: A mysqli object returned by mysqli_connect() or mysqli_init()

database

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_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 style

<?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]);

The above examples will output:

Default database is test.
Default database is world.

See Also

add a note

User Contributed Notes 1 note

up
0
Aravind Padmanabhan.
3 months ago
I have observed that sometimes .. directly using the db parameter in mysql::__construct doesn't work and it throws up a mysql server gone away error.

However if we first do a mysql connection without db and then use the mysql_select_db then it works.
To Top