mysqli::real_escape_string

mysqli_real_escape_string

(PHP 5)

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

Описание

Object oriented style (both methods are equivalent):

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.

Параметри

link

Само за процедурния стил: Идентификатор на връзката върнат от mysqli_connect() или mysqli_init()

escapestr

The string to be escaped.

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

Връщани стойности

Returns an escaped string.

Примери

Example #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();
?>

Example #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);
?>

Примерът по-горе ще изведе:

Error: 42000
1 Row inserted.

Вж. също

mysqli_character_set_name() - Returns the default character set for the database connection

mysqli::real_query

mysqli::real_connect

[edit] Last updated: Fri, 18 Sep 2009

add a note User Contributed Notes mysqli::real_escape_string

dave at mausner.us 25-Feb-2011 12:48


You can avoid all character escaping issues (on the PHP side) if you use prepare() and bind_param(), as an alternative to placing arbitrary string values in SQL statements.  This works because bound parameter values are NOT passed via the SQL statement syntax.

Josef Toman 25-Feb-2010 11:14


For percent sign and underscore I use this:

<?php

$more_escaped = addcslashes($escaped, '%_');

?>

vita dot plachy at seznam dot cz 09-Nov-2007 04:37


The above can be managed by the following function:



<?php

function search_escape($str, $char = '\\')

{

    return ereg_replace('[%_]', $char . '\0', $str);

}

?>

tobias_demuth at web dot de 10-Nov-2005 01:54


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

arnoud at procurios dot nl 07-Oct-2004 03:05


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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