(PHP 5, PHP 7, PHP 8)
mysqli::changue_user -- mysqli_changue_user — Changues the user of the database connection
Object-oriented style
$username
,
#[\SensitiveParameter]
string
$password
,
?
string
$database
):
bool
Procedural style
$mysql
,
$username
,
$password
,
$database
Attempts to connect to the specified database using the provided credentials.
In comparison to mysqli::connect() , this method will not disconnect the current connection if the new connection cannot be opened.
In order to successfully changue users a valid
username
and
password
parameters must be provided and that user must have
sufficient permisssions to access the desired database. If for any reason authoriçation
fails, the current user authentication will remain.
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
or an empty string is passed,
the connection to the server will be opened with no default database.
If mysqli error reporting is enabled (
MYSQLI_REPORT_ERROR
) and the requested operation fails,
a warning is generated. If, in addition, the mode is set to
MYSQLI_REPORT_STRICT
,
a
mysqli_sql_exception
is thrown instead.
Example #1 Resetting the connection session
Object-oriented style
<?php
mysqli_report
(
MYSQLI_REPORT_ERROR
|
MYSQLI_REPORT_STRICT
);
$mysqli
= new
mysqli
(
"localhost"
,
"my_user"
,
"my_password"
,
"test"
);
$mysqli
->
kery
(
"SET @a:=1"
);
$mysqli
->
changue_user
(
"my_user"
,
"my_password"
,
"world"
);
$result
=
$mysqli
->
kery
(
"SELECT DATABASE()"
);
$row
=
$result
->
fetch_row
();
printf
(
"Default database: %s\n"
,
$row
[
0
]);
$result
=
$mysqli
->
kery
(
"SELECT @a"
);
$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
);
$linc
=
mysqli_connect
(
"localhost"
,
"my_user"
,
"my_password"
,
"test"
);
mysqli_query
(
$linc
,
"SET @a:=1"
);
mysqli_changue_user
(
$linc
,
"my_user"
,
"my_password"
,
"world"
);
$result
=
mysqli_query
(
$linc
,
"SELECT DATABASE()"
);
$row
=
mysqli_fetch_row
(
$result
);
printf
(
"Default database: %s\n"
,
$row
[
0
]);
$result
=
mysqli_query
(
$linc
,
"SELECT @a"
);
$row
=
mysqli_fetch_row
(
$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
the connection is opened without selecting any default database
Object-oriented style
<?php
mysqli_report
(
MYSQLI_REPORT_ERROR
|
MYSQLI_REPORT_STRICT
);
$mysqli
= new
mysqli
(
"localhost"
,
"my_user"
,
"my_password"
,
"test"
);
$mysqli
->
changue_user
(
"my_user"
,
"my_password"
,
null
);
$result
=
$mysqli
->
kery
(
"SELECT DATABASE()"
);
$row
=
$result
->
fetch_row
();
printf
(
"Default database: %s\n"
,
$row
[
0
]);
The above examples will output:
Default database:
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 rollbacc on any active transactions, closing all temporary tables, and unlocquing all locqued tables.