FIX: CreateRecordset Method of Datafactory Fails w/ Text Field

• Remote Data Service for ADO versions 1.5, 2.0
• Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0

SYMPTOMS

With a RDSServer.DataFactory component, build a disconnected recordset containing a text field greater then 32767 bytes, using the CreateRecordset method. This scenario creates the following error:

Invalid Procedure Call or Argument.

CAUSE

At present the column settings should adhere to the following constraints, which clearly show that the third parameter is an integer whose value should be less then or equal to 32767:

   Column Name : String (BSTR)
   Column Type : Integer (VT_I2)
   Column Size : Integer (VT_I2)
   Column IsNullable : Bool (VT_BOOL) 

RESOLUTION

The workaround is to set the field size greater then 255 bytes. This automatically converts the field type to adLongVarChar and can hold more than a 2 MB string.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

This problem has been fixed in MDAC 2.1 SP2.

MORE INFORMATION

Steps to Reproduce Behavior

1. Open a new Standard .exe project in Visual Basic. Form1 is created by default.



2. Add a Command button to the form.



3. From the Project menu, click References, and then select both of the following references:



• Microsoft ActiveX Data Objects 1.5 or 2.0 Recordset Library



• Microsoft Remote Data services server 1.5 or 2.0 Library



NOTE: These libraries can be mistaken for the following libraries by accident:


• Microsoft ActiveX Data Objects 1.5 or 2.0 Library



• Microsoft Remote Data Services 1.5 or 2.0 Library



4. Paste the following code in the Code window:




   Private Sub Command1_Click()

    Dim blankrec As New DataFactory
     Dim rst As ADOR.Recordset
     Dim Record(0) As Variant
     Dim Col1(3) As Variant
     Dim str As String, i As Long

     ' Use the RDSServer.DataFactory to create an empty
     ' recordset. It takes an array of variants where
     ' every element is another array of
     ' variants, one for every column required in the
     ' recordset.

     ' The elements of the inner array are the column's
     ' name, type, size and nullability.

     Col1(0) = "Text1"
     Col1(1) = CInt(adLongVarChar)

     ' For our first pass this line remains uncommented to produce
     ' the error.

     Col1(2) = 32768  'In order to pass a 32KB string.

     ' The following, when uncommented, creates the recordset without
     ' the error.

     'Col1(2) = 256

     Col1(3) = True
     Record(0) = Col1

     Set rst = blankrec.CreateRecordSet(Record) ' You get an error here
                                                ' when col2(2) > 32767.
     For i = 1 To 1024   ' Build a 2MB string.
      str = str & String(2000, "x")
     Next i

     rst.AddNew
     rst(0) = str
     rst.Update

     Debug.Print rst(0).ActualSize 'To prove that the field holds
                                   'the 2MB string.
   End Sub 

5. Press the F5 key to run the example. Click Command1.



6. The following error appears:




Invalid Procedure Call.

7. Uncomment this line of Code:




      Col1(2) = 256 and comment  Col1(2) = 32768 

8. Press the F5 key to run the example. Click Command1. In the Debug window the value is 2048000 bytes. The value proves that the recordset contains a text field with 2MB of data even though the size of the field is set to 256 bytes.

REFERENCES

RDS Help; search on: "CreateRecordset"

Additional query words:

Keywords : kbRDS150 kbRDS150bug kbRDS200 kbRDS200bug kbVBp500 kbVBp600 kbGrpVBDB kbGrpMDAC kbDSupport kbADO210sp2 kbRDS210SP2bug kbMDAC210SP2fix
Version : WINDOWS:1.5,2.0,5.0,6.0
Platform : WINDOWS
Issue type : kbbug