PHP: Hypertext Preprocessor (original) (raw)
mysqli::change_user
mysqli_change_user
(PHP 5, PHP 7, PHP 8)
mysqli::change_user -- mysqli_change_user — Changes the user of the database connection
Description
Object-oriented style
In comparison to mysqli::connect(), this method will not disconnect the current connection if the new connection cannot be opened.
In order to successfully change users a valid username andpassword parameters must be provided and that user must have sufficient permissions to access the desired database. If for any reason authorization fails, the current user authentication will remain.
Parameters
mysql
Procedural style only: A mysqli object returned by mysqli_connect() or mysqli_init()
username
The MySQL user name.
password
The MySQL password.
database
The database name. If [null](reserved.constants.php#constant.null) or an empty string is passed, the connection to the server will be opened with no default database.
Return Values
Returns [true](reserved.constants.php#constant.true) on success or [false](reserved.constants.php#constant.false) on failure.
Examples
Example #1 Resetting the connection session
Object-oriented style
`<?php
mysqli_report
(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT); mysqli=newmysqli("localhost","myuser","mypassword","test");mysqli = new mysqli("localhost", "my_user", "my_password", "test");mysqli=newmysqli("localhost","myuser","mypassword","test");mysqli->query("SET @a:=1");$mysqli->change_user("my_user", "my_password", "world");$result = $mysqli->query("SELECT DATABASE()"); row=row = row=result->fetch_row();
printf("Default database: %s\n", row[0]);row[0]);row[0]);result = $mysqli->query("SELECT @a"); row=row = row=result->fetch_row();
if ($row[0] === null) {
printf("Value of variable a is NULL\n");
}`
Procedural style
`<?php
mysqli_report
(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT); link=mysqliconnect("localhost","myuser","mypassword","test");mysqliquery(link = mysqli_connect("localhost", "my_user", "my_password", "test");mysqli_query(link=mysqliconnect("localhost","myuser","mypassword","test");mysqliquery(link, "SET @a:=1");mysqli_change_user($link, "my_user", "my_password", "world");$result = mysqli_query($link, "SELECT DATABASE()"); row=mysqlifetchrow(row = mysqli_fetch_row(row=mysqlifetchrow(result);
printf("Default database: %s\n", row[0]);row[0]);row[0]);result = mysqli_query($link, "SELECT @a"); row=mysqlifetchrow(row = mysqli_fetch_row(row=mysqlifetchrow(result);
if ($row[0] === null) {
printf("Value of variable a is NULL\n");
}`
The above examples will output:
Default database: world Value of variable a is NULL
Example #2 If database is [null](reserved.constants.php#constant.null) the connection is opened without selecting any default database
Object-oriented style
`<?php
mysqli_report
(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT); mysqli=newmysqli("localhost","myuser","mypassword","test");mysqli = new mysqli("localhost", "my_user", "my_password", "test");mysqli=newmysqli("localhost","myuser","mypassword","test");mysqli->change_user("my_user", "my_password", null);$result = $mysqli->query("SELECT DATABASE()"); row=row = row=result->fetch_row();
printf("Default database: %s\n", $row[0]);`
The above examples will output:
Notes
Note:
Using this command will always cause the current database connection to behave as if was a completely new database connection, regardless of if the operation was completed successfully. This reset includes performing a rollback on any active transactions, closing all temporary tables, and unlocking all locked tables.
See Also
- mysqli_connect() - Alias of mysqli::__construct
- mysqli_select_db() - Selects the default database for database queries
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