PRB: Calculated Field Contents Cannot be Modified by ADO

Q241818


The information in this article applies to:


SYMPTOMS

Trying to modify the contents of a calculated field within an ActiveX Data Objects (ADO) recordset, generates the following error:

Runtime error '-2147217887(80040e21)' errors occurred.


CAUSE

Each calculated field in an ADO recordset contains the following attributes:

This indicates that the field cannot be modified.


RESOLUTION

Here are two ways to work around this behavior:


STATUS

This behavior is by design.


MORE INFORMATION

NOTE: Setting the adFldUnknownUpdatable and adFldUpdatable attribute flags is provider dependent. If the provider does not set the flags as indicated previously, you get a run-time error when you try to save the record.

The sample code below uses the publishers table in the pubs database that ships with SQL Server.

Steps to Reproduce Behavior

  1. Start a new Visual Basic project. Form1 is created by default. Create a reference to the Microsoft ActiveX Data Objects 2.x Library.


  2. Paste the following code in the General Declaration section of Form1:


  3. 
    Option Explicit
    Dim con As New ADODB.Connection
    Dim rs As New ADODB.Recordset
    
    Private Sub Form_Load()
    
    ' Connection String to your SQL Server
    con.ConnectionString = "Provider=SQLOLEDB.1;Data Source=sequel;User ID=sa;Password=;Initial Catalog=pubs;"
    con.Open
    
    rs.CursorLocation = adUseClient
    ' Concatenate a character 'A' onto the value retrieved from the field pub_name.
    rs.Open "SELECT pub_name + 'A' AS PN FROM Publishers", con, adOpenStatic, adLockBatchOptimistic, adCmdText
    
    MsgBox rs.RecordCount
    
    Debug.Print rs(0).Attributes And adFldUnknownUpdatable, _
                rs(0).Attributes And adFldUpdatable
    
    rs(0) = "Hello" ' <----- ERROR OCCURS HERE
    
    MsgBox "Passed!"
    
    End Sub 
  4. The code prints FALSE for each of the flags, adFldUnknownUpdatable and adFldUpdatable, indicating that the field is known to be non-updateable.


NOTE: Calculated columns are also read-only in Data Access Objects (DAO) and Remote Data Objects (RDO).


REFERENCES

For more information on how to use the Shape command to append a field to an ADO recordset, please refer to the following article in the Microsoft Knowledge Base:

Q223771 PRB: Appending Fields to a Recordset Generates an Error

© Microsoft Corporation 1999, All Rights Reserved.
Contributions by Ammar Abuthuraya, Microsoft Corporation

Additional query words: error -2147217887(80040e21)

Keywords : kbADO kbDatabase kbVBp600 kbGrpDSVBDB kbGrpDSMDAC kbDSupport kbADO210sp2 kbCodeSnippet kbMDAC260 kbADO260
Issue type : kbprb
Technology :


Last Reviewed: January 9, 2001
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