For most modern PHP projects, PDO is generally considered the better choice, but both have their strengths.
Here is a side-by-side comparison to help you decide:
Comparison at a Glance
| Feature | PDO (PHP Data Objects) | MySQLi (MySQL Improved) |
|---|---|---|
| Database Support | 12+ databases (MySQL, PostgreSQL, SQLite, Oracle, SQL Server, etc.) | MySQL / MariaDB only |
| Coding Style | Object-Oriented only | Both Object-Oriented and Procedural |
| Prepared Statements | Supports named parameters (:id, :status) and positional (?) | Positional only (?) |
| Parameter Binding | Clean: pass an array directly into execute() | Tedious: requires bind_param('ssi', ...) with type specifiers |
| Performance | Marginally slower (negligible difference in real-world apps) | Marginally faster for MySQL |
| Advanced MySQL Features | General DB features | Supports MySQL-specific features (e.g., async queries, multi-queries) |
Why PDO is Usually the Better Choice
- Simpler & Cleaner Prepared Statements: PDO lets you execute prepared statements with an associative array:php// PDO$stmt = $pdo->prepare(“SELECT * FROM users WHERE email = :email AND status = :status”);$stmt->execute([’email’ => $email, ‘status’ => $status]);$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);With MySQLi, you have to remember data type specifiers (
s,i,d,b):php// MySQLi$stmt = $mysqli->prepare(“SELECT * FROM users WHERE email = ? AND status = ?”);$stmt->bind_param(“si”, $email, $status);$stmt->execute();$rows = $stmt->get_result()->fetch_all(MYSQLI_ASSOC); - Database Portability: If your project ever needs to switch to PostgreSQL, SQLite, or SQL Server, you only need to change the connection string in PDO. With MySQLi, you would have to rewrite all database queries.
- Object Mapping: PDO has built-in support for mapping database results directly into custom PHP class objects using
PDO::FETCH_CLASS.
When to Choose MySQLi
- You are 100% certain you will only ever use MySQL/MariaDB.
- You need MySQL-specific features (such as asynchronous queries or
mysqli_multi_query). - You are maintaining legacy code that uses procedural PHP.
