How To Get More Information on the ODBC Call Failed Error

MORE INFORMATION

The DBEngine has an Errors collection that can be manipulated by the FOR- EACH construct. The JET Engine can store multiple errors in the DBEngine Errors collection. In Visual Basic 3.0, it was possible to parse the string using the routine shown on Page 175 of the Visual Basic 4.0 Professional Features Book under the "Guide to Data Access Objects" section. The # symbol was used to separate the "ODBC Call Failed" message from the detailed ODBC description in Visual Basic 3.0. However, this is not necessary under Visual Basic versions 4.0 and 5.0.

For the example below, a two-field table called MyTable has been set up on an ODBC Source and a primary key set on the ID Field. Two records have been added as below:

   Field      ID      Description
   ===============================
   Record 1    1      Hello
   Record 2    2      World
				

The code below will generate an error by trying to add a record with a duplicate primary key value to test the code:

1. Start a new Standard EXE project. Form1 is added by default.
2. Add a CommandButton to Form1.
3. Add the following code to the General Declarations section of Form1:

         Option Explicit
   
         Private Sub Command1_Click()
           Dim db As Database
           Dim rs As Recordset
           On Error GoTo trap
           Set db = OpenDatabase("")
           Set rs = db.OpenRecordset("Select * from MyTable")
           rs.AddNew
             rs.Fields(0).Value = 2
           rs.Update
           Exit Sub
         trap:
           MsgBox Errors.Count
           MsgBox Err.Number & " " & Err.Description
         End Sub
   					

4. Press the F5 key to run the project. Click on the CommandButton and you should receive error 3146, "ODBC Call Failed." Although the Error count is greater than one, only one message will be displayed.
5. Remove the code from within the error trap and replace it with one of the following error handlers:

         ' DAO Error Handler
         Dim MyError As Error
         MsgBox Errors.Count
         For Each MyError In DBEngine.Errors
           With MyError
             MsgBox .Number & " " & .Description
           End With
         Next MyError
   
         ' RDO Error Handler
         Dim MyError As rdoError
         MsgBox rdoErrors.Count
         For Each MyError In rdoEngine.rdoErrors
           With MyError
             MsgBox .Number & " " & .Description
           End With
         Next MyError
   
   					

6. Press the F5 key to run the project. You should see a detailed message and then the 3146 Error for "ODBC Call Failed."