ACC: Field Object Type Property Returns "Invalid Operation"

• Microsoft Access versions 2.0, 7.0

SYMPTOMS

Moderate: Requires basic macro, coding, and interoperability skills.

When you assign a variable to a property (such as Type) of a field object of an Index object, you receive the error message "Invalid Operation." This occurs for all properties except Name and Attributes.

This article assumes that you are familiar with Visual Basic for Applications and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information about Visual Basic for Applications, please refer to the "Building Applications" manual.

NOTE: Visual Basic for Applications (used in Microsoft Access for Windows 95, version 7.0) is called Access Basic in version 2.0.

CAUSE

Field objects of an Index object have a subset of the normal properties. The only valid properties are Name and Attributes, and the Attributes property has special values. For an Index object's field object, the Attributes property represents an ascending or descending sort order.

RESOLUTION

If you need to refer to other properties of the field object, use the TableDef field object. For example, to get the Type property you could use

x = tabledef.fields("myfield").properties("Type") 

x = tabledef.indexes("Myindex").fields("myfield").properties("Type") 

MORE INFORMATION

Steps to Reproduce Behavior

1. Open the sample database Northwind.mdb (or NWIND.MDB in version 2.0) and create a new module.



2. Enter the following line in the Declarations section of the module:




Option Explicit 

3. Enter the following code in the module:




Function FieldType ()
   Dim ws As WorkSpace
   Dim db As Database
   Dim tdef As TableDef
   Dim result As String
   Dim i As Integer

   ' Set up the environment.
   Set ws = DBEngine.Workspaces(0)
   Set db = ws.Databases(0)

   ' Main routine
   Set tdef = db.tabledefs("Employees")

   ' The line below results in "Invalid Operation."
   result = tdef.indexes("PrimaryKey").fields(0).properties("Type")
   Debug.Print result

   ' Cleanup
   db.Close
   ws.Close
End Function 

4. On the View menu, click Debug Window (Or Immediate window in version 2.0.



5. Type the following line, and then press ENTER:

   ? FieldType()

   Note the resulting error message.

REFERENCES

For more information about the Index object properties, search on "Index object," and then "Index Object, Indexes Collection Summary" using the Microsoft Access for Windows 95 Help Index.

For more information about the Index object properties in Access, version 2.0, search on "Index," and then "Index Object, Indexes Collection-Summary" using the Microsoft Access Help menu.

Additional query words:

Keywords : kberrmsg kbprg kbdta AccCon PgmObj
Version : WINDOWS:2.0,7.0
Platform : WINDOWS
Issue type : kbprb