mysqli_real_escape

Description

Procedural style:

string mysqli_real_escape_string ( mysqli link, string escapestr )

Object oriented style (method):

class mysqli {

string real_escape_string ( string escapestr )

}

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

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

返回值

Returns an escaped string.

参见

mysqli_character_set_name().

范例

例子 1. 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();
?>

例子 2. 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);
?>

上例将输出：

Error: 42000
1 Row inserted.

add a note User Contributed Notes

tobias_demuth at web dot de
11-Nov-2005 12:54


Note, that if no connection is open, mysqli_real_escape_string() will return an empty string!

arnoud at procurios dot nl
08-Oct-2004 12:05


Note that this function will NOT escape _ (underscore) and % (percent) signs, which have special meanings in LIKE clauses. 



As far as I know there is no function to do this, so you have to escape them yourself by adding a backslash in front of them.

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