Jet Data Access Objects

Data Access Objects, in the German documentary " data access objects", commonly referred to by the abbreviation " DAO ", is an interface library from Microsoft for accessing data and structures of databases, specifically Microsoft Access databases (MDBs ).

Up to and including Access 97 DAO library was the standard library for technical programming access to the database objects and data in Access itself In Access 2000, Access 2002 ( Office XP) and Access 2003 DAO still included for compatibility reasons only ( in the version 3.6), as a standard library was provided ADO. DAO but is popular with Access developers is still very popular, including as it access to specific parts of Access allowed as ADO.

In Access 2007, the DAO library under the new long - term " Access Database Engine Object Library " with the version number 12.0 ( Filename: ACEDAO.DLL, qualifier in the code continues: DAO) again standard library for accessing database objects and data in MDS.

The DAO library offers a two-part object hierarchy: Starting from the base object " DBEngine " there is " Workspace " objects of type "Jet Workspace " ( to access MDBs) and " ODBCDirect Workspace " (since DAO 3.5 library to access ODBC data sources ) with different child objects.

A "Jet Workspace " contains " Database " objects that represent MDBs. The data structure of the MDB can " TableDef " - " Relations" - and " QueryDef " objects are accessed, the data on "Recordset " objects. Furthermore, there are "User" -, " Group" -, "container" - and "Document" objects for the access to the system of rights of access. In version 12.0, the latter objects ( or their properties and methods that are specific to the system of rights ) but completely hidden. A "Jet Workspace " uses the libraries of the jet engine for the actual execution.

A " ODBCDirect Workspace " provides an alternative to the "Database " objects "Connection" objects, including but only Recordset and Connection objects in, QueryDef objects. A " ODBCDirect Workspace " accesses via the RDO library to the ODBC API. Version 12.0 supports the " ODBCDirect Workspace " according to the documentation and no longer refers to ADO for accessing ODBC data sources.

MS Office XP provides a DAO with PIA as an interface for the. NET world.