Utilizing PDO Array Parameters with LIMIT Clauses

In PHP, employing PDO to execute database queries with an array of parameters and a LIMIT clause can pose challenges. Let's explore how to effectively address this situation.

Background:
The issue arises when attempting to execute a query with a LIMIT clause while utilizing an array to pass parameters to the PDOStatement. By default, the :limit1 and :limit2 placeholders in the LIMIT clause do not function as expected if bindParam() is used to bind them.

Solution:
The key to resolving this issue is to disable the default PDO::ATTR_EMULATE_PREPARES setting. When this setting is enabled, PHP emulates prepared statements rather than genuinely using them. This means that the placeholders (:limit1, :limit2) are not interpreted as parameters, leading to the observed behavior.

Code Snippet:
To resolve the issue, add the following code before executing the query:

$pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

This disables prepared statement emulation, allowing you to pass parameters through an array while utilizing the LIMIT clause effectively.

$sql = "SELECT * FROM table WHERE id LIKE CONCAT('%', :id, '%')
LIMIT :limit1, :limit2";

$stmt = $pdo->prepare($sql);
$stmt->execute(array(5));

Additional Performance Considerations:

Disabling PDO::ATTR_EMULATE_PREPARES may impact performance. Prepared statements are generally more efficient than emulated ones. However, if you encounter issues with parameter passing or LIMIT clauses, disabling emulation may be a necessary trade-off.

Further Reading:

For more in-depth information on this topic, refer to the following resources:

• [PDO MySQL: Use PDO::ATTR_EMULATE_PREPARES or not?](https://suleimanbader.wordpress.com/2008/03/09/pdo-mysql-use-pdoattremu lateprepares-or-not/)