(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.2.1)
PDO::quote — Quotes a string for use in a query
$string, int $type = PDO::PARAM_STR): string|falsePDO::quote() places quotes around the input string (if required) and escapes special characters within the input string, using a quoting style appropriate to the underlying driver.
If you are using this function to build SQL statements, you are strongly recommended to use PDO::prepare() to prepare SQL statements with bound parameters instead of using PDO::quote() to interpolate user input into an SQL statement. Prepared statements with bound parameters are not only more portable, more convenient, immune to SQL injection, but are often much faster to execute than interpolated queries, as both the server and client side can cache a compiled form of the query.
Not all PDO drivers implement this method (notably PDO_ODBC). Consider using prepared statements instead.
The character set must be set either on the server level, or within the database connection itself (depending on the driver) for it to affect PDO::quote(). See the driver-specific documentation for more information.
stringThe string to be quoted.
type
Provides a hint to the type of data for drivers that have alternate quoting
styles. For example PDO_PARAM_LOB will tell the driver to
escape binary data.
Returns a quoted string that is theoretically safe to pass into an
SQL statement. Returns false if the driver does not support quoting in
this way.
Example #1 Quoting a normal string
<?php
$conn = new PDO('sqlite:/home/lynn/music.sql3');
/* Simple string */
$string = 'Nice';
print "Unquoted string: $string\n";
print "Quoted string: " . $conn->quote($string) . "\n";
?>
The above example will output:
Unquoted string: Nice Quoted string: 'Nice'
Example #2 Quoting a dangerous string
<?php
$conn = new PDO('sqlite:/home/lynn/music.sql3');
/* Dangerous string */
$string = 'Naughty \' string';
print "Unquoted string: $string\n";
print "Quoted string:" . $conn->quote($string) . "\n";
?>
The above example will output:
Unquoted string: Naughty ' string Quoted string: 'Naughty '' string'
Example #3 Quoting a complex string
<?php
$conn = new PDO('sqlite:/home/lynn/music.sql3');
/* Complex string */
$string = "Co'mpl''ex \"st'\"ring";
print "Unquoted string: $string\n";
print "Quoted string: " . $conn->quote($string) . "\n";
?>
The above example will output:
Unquoted string: Co'mpl''ex "st'"ring Quoted string: 'Co''mpl''''ex "st''"ring'