PDO::query
Despite the recommendation above that you are "strongly recommended" to use PDO::prepare(), using PDO::quote() with PDO::query() is significantly faster than using prepared statements (unless you're submitting many identical queries in a sequence). Test data from several sources shows about a 2-3x speed penalty for using prepared queries if you are only submitting a single query, and prepared queries only have a speed advantage when you are submitting thousands of queries from prepared statement at once.
It's also more convenient since less lines of code are required and you don't have to deal with the challenge of keeping all your ?'s properly ordered to match a separate parameter list as you do with prepared statements.
So don't let the wording of the description scare you away from using this method.
PDO::quote
(PHP 5 >= 5.1.0, PECL pdo >= 0.2.1)
PDO::quote — Quotes a string for use in a query.
Opis
string PDO::quote
( string
$string
[, int $parameter_type = PDO::PARAM_STR
] )PDO::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.
Parametry
-
string -
The string to be quoted.
-
parameter_type -
Provides a data type hint for drivers that have alternate quoting styles.
Zwracane wartości
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.
Przykłady
Przykład #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";
?>
Powyższy przykład wyświetli:
Unquoted string: Nice Quoted string: 'Nice'
Przykład #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";
?>
Powyższy przykład wyświetli:
Unquoted string: Naughty ' string Quoted string: 'Naughty '' string'
Przykład #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";
?>
Powyższy przykład wyświetli:
Unquoted string: Co'mpl''ex "st'"ring Quoted string: 'Co''mpl''''ex "st''"ring'
Zobacz też:
- PDO::prepare() - Prepares a statement for execution and returns a statement object
- PDOStatement::execute() - Executes a prepared statement
add a note
User Contributed Notes
PDO::quote
orrd101 at gmail dot com
30-Apr-2012 01:15
hungry dot rahly at gmail dot com
27-Sep-2010 09:31
For those of you who do want to have null returned as NULL, it is fairly easy to add.
<?php
class Real_PDO extends PDO {
public function quote($value, $parameter_type = PDO::PARAM_STR ) {
if( is_null($value) ) {
return "NULL";
}
return parent::quote($value, $parameter_type);
}
}
?>
then all you have to do is change your creation of the PDO object to this new class, and you shouldn't have to change any other function calls. The nice thing about this method is that you can override any PDO function or add your own. IMO, PDO should natively handle this, as there is a difference in databases between NULL and an empty string(''), the quoting of numeric values is another issue altogether.
php at deobald dot org
20-May-2008 08:33
Note that this function just does what the documentation says: It escapes special characters in strings.
It does NOT - however - detect a "NULL" value. If the value you try to quote is "NULL" it will return the same value as when you process an empty string (-> ''), not the text "NULL".