Proper way to create a DAO in PHP

Question

From an OOP perspective, what is the proper way to create a DAO (Data Access Object) in php?

For example (using Account as a basic example), my AccountDAO will have some of the following functions:

• GetAllAccounts
• GetAccountByID
• UpdateAccount
• DeleteAccount
• InsertAccount

So once I fetch all of the Accounts in the database, should I return them to the caller as an array of account objects? Should I just return the mysql result set?

Do you know any good example of a DAO?

Answer 1

You are on the right track to build a DAO: the methods you listed should definitely be part of a DAO.

To answer your specific question, a DAO should not leak any database specific objects, it can leak some database concepts though as long as they are not specific to a database vendor.

So no, you should not return a MySQL result set. But you could create a generic result set that wraps a MySQL result set and that may work with higher level concepts (extracting whole objects instead of extracting columns).

Edit: My intent is not to lead you to actually build a result set wrapper, you could also simply return an array of objects like you initially suggested. This was just an example.