Share via

DBEngine Object (DAO)

  • Article

The DBEngine object is the top level object in the DAO object model.

Remarks

The DBEngine object contains and controls all other objects in the hierarchy of DAO objects. You can't create additional DBEngine objects, and the DBEngine object isn't an element of any collection.

With any type of database or connection, you can:

  • Use the Version property to obtain the DAO version number.

  • Use the LoginTimeout property to obtain or set the ODBC login timeout, and the RegisterDatabase method to provide ODBC information to the Microsoft Access database engine.

  • Use the DefaultPassword and DefaultUser properties to set the user identification and password for the default Workspace object.

  • Use the CreateWorkspace method to create a new Workspace object. You can use optional arguments to override the settings of the DefaultType, DefaultPassword, and DefaultUser properties.

  • Use the OpenDatabase method to open a database in the default Workspace, and use the BeginTrans, Commit, and Rollback methods to control transactions on the default Workspace.

  • Use the Workspaces collection to reference specific Workspace objects.

  • Use the Errors collection to examine data access error details.

Other properties and methods are only available when you use DAO with the Microsoft Access database engine. You can use them to control the Microsoft Access database engine, manipulate its properties, and perform tasks on temporary objects that aren't elements of collections. For example, you can:

  • Use the CreateDatabase method to create a new Microsoft Access database engine Database object.

  • Use the Idle method to enable the Microsoft Access database engine to complete any pending tasks.

  • Use the CompactDatabase and RepairDatabase methods to maintain database files.

  • Use the IniPath and SystemDB properties to specify the location of Microsoft Access database engine Windows Registry information and the Microsoft Access workgroup information file, respectively. The SetOption method allows you override windows registry settings for the Microsoft Access database engine.

After you change the DefaultType and IniPath property settings, only subsequent Workspace objects will reflect these changes.

To refer to a collection that belongs to the DBEngine object, or to refer to a method or property that applies to this object, use this syntax:

[DBEngine.][collection | method | property]

Example

This example enumerates the collections of the DBEngine object.

Sub DBEngineX() 
 
 Dim wrkLoop As Workspace 
 Dim prpLoop As Property 
 
 With DBEngine 
 Debug.Print "DBEngine Properties" 
 
 ' Enumerate Properties collection of DBEngine, 
 ' trapping for properties whose values are 
 ' invalid in this context. 
 For Each prpLoop In .Properties 
 On Error Resume Next 
 Debug.Print " " & prpLoop.Name & " = " _ 
 & prpLoop 
 On Error GoTo 0 
 Next prpLoop 
 
 Debug.Print "Workspaces collection of DBEngine" 
 
 ' Enumerate Workspaces collection of DBEngine. 
 For Each wrkLoop In .Workspaces 
 Debug.Print " " & wrkLoop.Name 
 
 ' Enumerate Properties collection of each 
 ' Workspace object, trapping for properties 
 ' whose values are invalid in this context. 
 For Each prpLoop In wrkLoop.Properties 
 On Error Resume Next 
 Debug.Print " " & prpLoop.Name & _ 
 " = " & prpLoop 
 On Error GoTo 0 
 Next prpLoop 
 
 Next wrkLoop 
 
 End With 
 
End Sub