This article was previously published under Q289664
Moderate: Requires basic macro, coding, and interoperability skills.
This article applies to a Microsoft Access database (.mdb) and to a Microsoft Access project (.adp).
For a Microsoft Access 97 version of this article, see 182342.
For a Microsoft Access 2000 version of this article, see 202192.
When you compile or run code, you may receive the following error message:
Compile Error: User-defined type not defined.
You are referring to an object in an object library that you do not have referenced.
You must add a reference to the object library that contains the object that you are using in code. To do so, follow these steps:
Open any module in the database that is generating the error that is described in the "Symptoms" section of this article.
On the Debug menu, click Compile <database name>. Note the line of code that is highlighted when you receive the error message.
On the Tools menu, click References.
Click to select the object library that contains the object that is referenced by the line of code that is highlighted.
NOTE: This section references Microsoft DAO. DAO is not used in Microsoft Access projects (*.adp), but the same concepts regarding missing object libraries apply.
Not having a reference to the Microsoft DAO Object Library is one of the most common reasons for the error that is described in the "Symptoms" section of this article in Access databases (*.mdb). If the reference is missing, you may receive this error on many common DAO commands such as:
Dim db as DAO.Database
If you receive this error on a common DAO object, you must add the following reference:
Microsoft DAO 3.6 Object Library
Explicitly Declaring DAO and ADO Objects
A common reference conflict occurs when you have references to both the Microsoft DAO Object Library (DAO) and the Microsoft ActiveX Data Objects Library (ADO). This is because these two libraries contain objects with the same name, such as Recordset. To avoid any compile errors in the case where you add another object library reference that uses the same object names, it is good practice to include "DAO." in the declaration of any DAO objects. Likewise, when declaring ADO objects, include "ADODB." in the declaration. The following example uses the Recordset object to illustrate this point:
Example 1: DAO Objects
Reference: Microsoft DAO 3.6 Object Library Declaration: Dim myRecordset as DAO.Recordset
Example 2: ADO Objects
Reference: Microsoft ActiveX Data Objects 2.1 Library Declaration: Dim myRecordset as ADODB.Recordset
NOTE: By explicitly declaring the object as ADODB or DAO, the position of the checked reference on the references list is not an issue.
Steps to Reproduce the Behavior
Create a module, and then type or paste the following procedure:
Function Test() Dim db as DAO.DatabaseEnd Function
On the Tools menu, click References, and then click to clear the Microsoft DAO Object Library check box in the References dialog box.
To test this function, type the following line in the Immediate window, and then press ENTER:
Note that you receive the error message that is mentioned in the "Symptoms" section of this article.
For more information about ActiveX Data Objects (ADO), in the Visual Basic Editor, click Microsoft Visual Basic Help on the Help menu, type ActiveX Data Objects in the Office Assistant or the Answer Wizard, and then click Search to view the topic.