How to Securely Use PDO Parameterized Queries with LIKE Statements?

Using PDO Parameterized Query with LIKE Statement

In working with databases, performing search operations efficiently and securely is paramount. One approach to enhance search precision and prevent SQL injection vulnerabilities is to utilize parameterized queries. This article addresses the specific scenario of constructing a LIKE statement using PDO parameterized queries.

Background

You may encounter a situation where you need to query data using a LIKE statement, which allows you to search for partial matches based on a specified pattern. While crafting such queries, it's crucial to employ parameterized queries to protect against SQL injection attacks.

Initial Attempt

You attempted to construct a parameterized LIKE query as follows:

$query = $database->prepare('SELECT * FROM table WHERE column LIKE "?%"');
$query->execute(array('value'));

However, this attempt would not produce expected results because the pattern provided in the query is enclosed in double quotes ("). PDO interpreted the double quotes as part of the pattern, leading to incorrect matching behavior.

Optimized Solution

The correct approach involves parameterizing the LIKE statement without enclosing the pattern in double quotes, as demonstrated below:

$query = $database->prepare('SELECT * FROM table WHERE column LIKE ?');
$query->execute(array('value%'));

By omitting the double quotes, the placeholder (?) is considered a variable, and the provided value ('value%') is correctly appended as a pattern for matching. This ensures accurate LIKE search behavior and maintains security by preventing malicious input from affecting query execution.

Conclusion

Constructing parameterized LIKE queries in PDO is a crucial aspect of database manipulation for efficient and secure data retrieval. This article walked you through both an initial attempt and an optimized solution, highlighting the significance of proper parameterization when working with LIKE statements in PHP.

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