Data Access Objects (Dao) are are used for executing database queries. The subclasses of PntDao are so that the same methods will givo sort of the same result on different kinds of databases. Sort of, because different database may require different dialects of SQL and the pntDao subclasses do currently not take care of that. However, if database abstraction is needed in the future to transparently store and search different types of (SQL) databases, the Dao classes will be used to implement it polymophically.
Data Access Objects are much like PHP Data Objects (PDO) but can be extended to wrap Vendor Specific Database Extensions and offer some rudumentary Sql generation used by the framework.
Data Acess Object class for the original MySQL API. With phpPeanuts <= 2.0.0a this was the default Dao. As the PHP documentation no longer recommends the use of this API, we now recommend the use of PntPdoDao with MySql for PHP >= 5.1.
Data Access Object class for PHP Data Objects (PDO). For PHP >= 5.1 PDO offers access to several databases. Since phpPeanuts 2.1 PntPdoDao is the default Dao class of phpPeanuts and the recommended class to access MySql.
Limitation: not all database drivers support the entire PDO api. This limits the use of some PDO drivers with phpPeanuts < 2.2 , see the limitations in the release notes of your version of phpPeanuts.
Data Acess Object class for the old SQLite extension that provides access to SQLite 2 databases. Beginning with PHP 5.4, the SQLite extension is available only via PECL. For SQLite 3 databases a PDO driver is available that can be acessed throuth PntPdoDao.