MySQL and PHP Reference :: 3 MySQL Improved Extension (Mysqli) :: 3.9 The mysqli class (mysqli) :: 3.9.42 mysqli::real_escape_string, mysqli_real_escape_string

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3.9.42. `mysqli::real_escape_string`, `mysqli_real_escape_string`

mysqli::real_escape_string
mysqli_real_escape_string
Escapes special characters in a string for use in an SQL statement, taking into account the current charset of the connection

Description

Object oriented style

string mysqli::escape_string(string escapestr);
string mysqli::real_escape_string(string escapestr);

Procedural style

string mysqli_real_escape_string(mysqli link,
                                 string escapestr);

This function is used to create a legal SQL string that you can use in an SQL statement. The given string is encoded to an escaped SQL string, taking into account the current character set of the connection.

Security: the default character set

The character set must be set either at the server level, or with the API function mysqli_set_charset for it to affect mysqli_real_escape_string. See the concepts section on character sets for more information.

Parameters

link

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

escapestr

The string to be escaped.

Characters encoded are NUL (ASCII 0), \n, \r, \, ', ", and Control-Z.

Return Values

Returns an escaped string.

Examples

Example 3.63. mysqli::real_escape_string example

Object oriented style

<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
$mysqli->query("CREATE TEMPORARY TABLE myCity LIKE City");
$city = "'s Hertogenbosch";
/* this query will fail, cause we didn't escape $city */
if (!$mysqli->query("INSERT into myCity (Name) VALUES ('$city')")) {
    printf("Error: %s\n", $mysqli->sqlstate);
}
$city = $mysqli->real_escape_string($city);
/* this query with escaped $city will work */
if ($mysqli->query("INSERT into myCity (Name) VALUES ('$city')")) {
    printf("%d Row inserted.\n", $mysqli->affected_rows);
}
$mysqli->close();
?>

Procedural style

<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
mysqli_query($link, "CREATE TEMPORARY TABLE myCity LIKE City");
$city = "'s Hertogenbosch";
/* this query will fail, cause we didn't escape $city */
if (!mysqli_query($link, "INSERT into myCity (Name) VALUES ('$city')")) {
    printf("Error: %s\n", mysqli_sqlstate($link));
}
$city = mysqli_real_escape_string($link, $city);
/* this query with escaped $city will work */
if (mysqli_query($link, "INSERT into myCity (Name) VALUES ('$city')")) {
    printf("%d Row inserted.\n", mysqli_affected_rows($link));
}
mysqli_close($link);
?>

The above examples will output: