Data Access Object (DAO)

Data Access Object (DAO):

The Microsoft Data Access Object (DAO) is an approach of database programming which is similar to ODBC. In this approach instead of using CRecordset and CDatabase, we use CDaoRecordset and CDaoDatabase.

Features of DAO are –

1.     DAO is a set of COM interface. These interfaces are set of pure virtual functions.

2.     The required COM model is located in DAO350.DLL.

3.     It has support for Jet Database engine.

4.     The Visual Basic Application (VBA) Automation controller can use DAO object and can make use of the DAO Library.

5.     The MFC classes are used to implement the concept of DAO. The MFC database classes for DAO are –

i.                    CDaoDatabase: An interface for using database.

ii.                  CDaoWorkspace: An interface for managing the single user connectivity with the database.

iii.                CDaoRecordset: An interface for accessing records.

iv.               CDaoTableDef: An interface for manipulating the base table.

v.                 CDaoQueryDef: An interface used to execute queries on database.

Types of Database that can be opened with DAO-

1.     Access Database

2.     ODBC Database Source

3.     ISAM-Type Database Source

4.     External Tables