How to Use DAO in Excel Without Referencing DAO Library (152400)



The information in this article applies to:

  • Microsoft Excel 97 for Windows
  • Microsoft Excel for Windows 95

This article was previously published under Q152400

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
				
would generate the "User-defined type not defined" error. However, the following statement does not:
   Dim Db as Object
				

Visual Basic Code Example

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. 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.
  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

For more information about creating a DAO reference in Microsoft Excel 97, from the Visual Basic Editor, click the Office Assistant, type Dao reference click Search, and then click to view "What you need to create Visual Basic macros that retrieve external data."

NOTE: If the Assistant is hidden, click the Office Assistant button on the Standard toolbar. If the Assistant is not able to answer your query, please see the following article in the Microsoft Knowledge Base:

176476 OFF: Office Assistant Not Answering Visual Basic Questions

"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.

Modification Type:MinorLast Reviewed:10/10/2006
Keywords:kbProgramming KB152400