A data access layer (DAL) in computer software is a layer of a computer program which provides simplified access to data stored in persistent storage of some kind, such as an entity-relational database.
For example, the DAL might return a reference to an object (in terms of object-oriented programming) complete with its attributes instead of a row of fields from a database table.
This kind of model could be implemented by creating a class of data access methods that directly reference a corresponding set of database stored procedures.
The procedures would be called from a method inside the class, which would return an object containing the requested values.
Or, the insert, delete and update commands could be executed within simple functions like registeruser or loginuser stored within the data access layer.