XL: How to Use DAO in Excel Without Referencing DAO Library

• Microsoft Excel for Windows 95, version 7.0, 7.0a
• Microsoft Excel 97 for Windows

SYMPTOMS

In Microsoft Excel, if you attempt to use data access objects (DAO) without first referencing the Microsoft DAO 3.0 or 3.5 Object Library, you may receive an error message. This can cause difficulties when you are developing applications for distribution.

WORKAROUND

Instead of referencing the Microsoft DAO 3.0 or 3.5 Object Library, you can use object linking and embedding (OLE) to create a database engine object. You can then use the database engine object in references to the database. In this way, you do not have to create a reference to the Microsoft DAO 3.0 or 3.5 Object Library file.

This method does have a limitation. You can only declare your database variables as the generic Object type. For example, the statement

   Dim Db as Database

   Dim Db as Object

Visual Basic Code Example

The following code example shows how to declare and use the database engine. The example assumes you have the Northwind.mdb sample database installed in c:\MSOffice\Access\Samples.

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   Sub DaoWithoutReferences()

       'Declare variables.
       Dim dbEng As Object
       Dim Db As Object
       Dim Rs As Object

       'Set the dbEng object using OLE
       Set dbEng = CreateObject("DAO.DBEngine")

       'NOTE: In Microsoft Excel 97, use this line of code instead of the
       'above line of code:
       '
       '   Set dbEng = CreateObject("DAO.DBEngine.35")

       'Open a database. Note that the statement contains the dbEng object.
       Set Db = _
           dbEng.workspaces(0).opendatabase("c:\MSOffice\Access\" & _
           "Samples\Northwind.mdb")

       'Open a recordset in the database.
       Set Rs = Db.openrecordset("Customers")

       'Perform a move last and find the number of records
       'in the database to test if the operation worked.
       Rs.movelast
       MsgBox Rs.recordcount

       Set Rs = Nothing
       Set Db = Nothing
       Set dbEng = Nothing

   End Sub

REFERENCES

"Developing Microsoft Excel 95 Solutions with Visual Basic for Applications," Chapter 7, "Database Access and Messaging", page 489.

DAO Reference library, "DBEngine Object"

For more information about DAO, establish a reference to the "Microsoft DAO 3.0 Object Library". Then on the View menu, click Object Browser. Under Libraries/Workbooks, select DAO, and under Objects/Modules, click DBEngine.