This class can access different types of SQL database using PDO. It provides a common interface to access different types of database like MySQL, PostgreSQL, Microsoft SQL server, IBM DB2, SQLite, Oracle, Informix, and Firebird. The class can establish connections, execute queries, retrieve single result rows or single row columns, the number of result rows, the last inserted record identifier, the names of tables columns, and execute INSERT, UPDATE and DELETE queries from parameters. It can use prepared queries to prevent SQL injection attacks.