SQLite3

SQLite is a C-language library that implements a small, fast, self-contained, high-reliability, full-featured, SQL database engine.

The related extension is SQLite3. It allows the creation and usage of file-based or memory-based databases.

SQLite3 is also available with PDO, with the pdo_sqlite engine.

<?php

    $db = new SQLite3('my.sqlite3');

    $results = $db->query('SELECT bar FROM foo');
    while ($row = $results->fetchArray()) {
        var_dump($row);
    }

?>

Documentation

See also SQLite3 in PHP and How to Store Images in SQLite with PHP.

Related : Structured Query Language (SQL), SQL Database, PHP Data Objects (PDO), Relational DataBase Management System (RDBMS)