PHP mysqli: change_user() Function
mysqli_change_user() function / mysqli::change_user
The mysqli_change_user() function / mysqli::change_user changes the user of the specified database connection, and sets the current database.
Syntax:
Object oriented style
bool mysqli::change_user ( string $user , string $password , string $database )
Procedural style
bool mysqli_change_user ( mysqli $link , string $user , string $password , string $database )
Usage: Procedural style
mysqli_change_user(connection,username,password,dbname);
Parameter:
Name | Description | Required/Optional |
---|---|---|
connection | Specifies the MySQL connection to use. | Required |
username | Specifies the MySQL username | Required |
password | Specifies the MySQL password | Required |
dbname | Specifies the database to change to | Required |
Return value:
Returns TRUE on success or FALSE on failure.
Version: PHP 5, PHP 7
Example of object oriented style:
<?php
/* connect database test */
$mysqli = new mysqli("localhost", "user1", "datasoft123", "hr");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
/* Set Variable a */
$mysqli->query("SET @a:=1");
/* reset all and select a new database */
$mysqli->change_user("my_user", "my_password", "world");
if ($result = $mysqli->query("SELECT DATABASE()")) {
$row = $result->fetch_row();
printf("Default database: %s\n", $row[0]);
$result->close();
}
if ($result = $mysqli->query("SELECT @a")) {
$row = $result->fetch_row();
if ($row[0] === NULL) {
printf("Value of variable a is NULL\n");
}
$result->close();
}
/* close connection */
$mysqli->close();
?>
Output:
Default database: hr Value of variable a is NULL
Example of procedural style:
<?php
/* connect database test */
$link = mysqli_connect("localhost", "user1", "datasoft123", "hr");
/* check connection */
if (!$link) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
/* Set Variable a */
mysqli_query($link, "SET @a:=1");
/* reset all and select a new database */
mysqli_change_user($link, "user1", "datasoft123", "hr");
if ($result = mysqli_query($link, "SELECT DATABASE()")) {
$row = mysqli_fetch_row($result);
printf("Default database: %s\n", $row[0]);
mysqli_free_result($result);
}
if ($result = mysqli_query($link, "SELECT @a")) {
$row = mysqli_fetch_row($result);
if ($row[0] === NULL) {
printf("Value of variable a is NULL\n");
}
mysqli_free_result($result);
}
/* close connection */
mysqli_close($link);
?>
Output:
Default database: hr Value of variable a is NULL
See also
Previous: begin_transaction
Next: character_set_name
PHP: Tips of the Day
var_export(): var_export() dumps a PHP parseable representation of the item.
You can pass true as the second parameter to return the contents into a variable.
Example:
<?php $myarray = [ "PHP", "Tips" ]; $mystring = "PHP Tips"; $myint = 28; var_export($myarray); var_export($mystring); var_export($myint); ?>
Output:
array ( 0 => 'PHP', 1 => 'Tips', )'PHP Tips'28
To put the content into a variable, you can do this:
$array_export = var_export($myarray, true); $string_export = var_export($mystring, true); $int_export = var_export($myint, 1); // any `Truthy` value
After that, you can output it like this:
printf('$myarray = %s; %s', $array_export, PHP_EOL); printf('$mystring = %s; %s', $string_export, PHP_EOL); printf('$myint = %s; %s', $int_export, PHP_EOL);
Example:
<?php $myarray = [ "PHP", "Tips" ]; $mystring = "PHP Tips"; $myint = 28; $array_export = var_export($myarray, true); $string_export = var_export($mystring, true); $int_export = var_export($myint, 1); printf('$myarray = %s; %s', $array_export, PHP_EOL); printf('$mystring = %s; %s', $string_export, PHP_EOL); printf('$myint = %s; %s', $int_export, PHP_EOL); ?>
This will produce the following output:
Output:
$myarray = array ( 0 => 'PHP', 1 => 'Tips', ); $mystring = 'PHP Tips'; $myint = 28;
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