mysqli::real_escape_string
mysqli::escape_string
mysqli_real_escape_string
(PHP 5, PHP 7)
mysqli::real_escape_string -- mysqli::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
$escapestr
) : stringProcedural style
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.
Errors/Exceptions
Executing this function without a valid MySQLi connection passed in will
return NULL and emit E_WARNING level errors.
Examples
Example #1 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:
Error: 42000 1 Row inserted.
Notes
Note:
For those accustomed to using mysql_real_escape_string(), note that the arguments of mysqli_real_escape_string() differ from what mysql_real_escape_string() expects. The
linkidentifier comes first in mysqli_real_escape_string(), whereas the string to be escaped comes first in mysql_real_escape_string().
See Also
- mysqli_set_charset() - Sets the default client character set
- mysqli_character_set_name() - Returns the default character set for the database connection
English translation
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Document created the 30/01/2003, last modified the 26/10/2018
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References
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