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 (PHP 5)
string mysqli_real_escape_string ( mysqli link, string escapestr )

Procedural style:

Object oriented style (method):

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.

范例

例 1319. 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 1320. 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.