How to Resolve Error When Passing Array Parameters with LIMIT Clause in PDO?

Passing Array of PDO Parameters with LIMIT Clause

Introduction:

When working with PDO, it can be challenging to pass an array of parameters and use the LIMIT clause simultaneously. This article provides a solution to this issue.

Problem Statement:

Given the following SQL query:

SELECT * FROM table WHERE id LIKE CONCAT('%', :id, '%')
LIMIT :limit1, :limit2

You want to execute this query using an array of parameters, as seen below:

$stmt->execute($array);

However, using the bindParam() method for the LIMIT parameters (:limit1 and :limit2) results in an error.

Solution:

The solution lies in disabling the default PDO setting of PDO::ATTR_EMULATE_PREPARES. This setting essentially instructs PDO to emulate prepared statements, rather than using them natively.

To disable this setting:

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

Once this setting is disabled, the query can be prepared and executed with the array of parameters, including the LIMIT values:

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

Implications:

Disabling PDO::ATTR_EMULATE_PREPARES can improve performance, as it removes the overhead of emulating prepared statements. However, it should be noted that this setting is enabled by default due to performance reasons.

Additional Resources:

• [PDO MySQL: Use PDO::ATTR_EMULATE_PREPARES or not?](https://pdosql.org/pdo-mysql-use-pdo-attr-emulate-prepares-or-not/)

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