ACC: RecordsAffected Property Incorrect for SQL Pass-Through

• Microsoft Access versions 7.0, 97

SYMPTOMS

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

When you use the RecordsAffected property of a Database or QueryDef object to determine the number of records affected by the Execute method, the value is incorrect with SQL pass-through queries.

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 your version of the "Building Applications with Microsoft Access" manual.

CAUSE

The RecordsAffected property is not set when you execute a pass-through query.

STATUS

This behavior is by design.

MORE INFORMATION

When you view the RecordsAffected property, it reflects the number of records affected by the most recent Execute method on an object that uses the Microsoft Jet database engine. Pass-through queries bypass the Jet database engine and interact directly with the back-end database through the ODBC driver.

The following example shows a correct RecordsAffected value because the Execute method operates on a table in the sample database Northwind.mdb:

1. Start Microsoft Access and open the sample database Northwind.mdb.

2. Create a module and type the following procedure:

         Sub ViewRecs()
            Dim db As DATABASE
            ' Substitute the correct path to Northwind.mdb on your computer.
            Set db = DBEngine.Workspaces(0).OpenDatabase _
            ("C:\Program Files\Microsoft Office\Office\Samples\Northwind.mdb")
            db.Execute "Update employees set country = 'United States' " _
             & "where country = 'USA';"
            Msgbox db.RecordsAffected
         End Sub
   
   

3. To test this procedure, type the following line in the Debug window, and then press ENTER.

          ViewRecs
   

   Note that a message box opens and displays the number of records affected by the update. The number is 5 in an unaltered copy of Northwind.mdb.

Steps to Reproduce Behavior

The following example uses an ODBC connection to the Pubs database in Microsoft SQL Server. Substitute the correct parameters for your ODBC database in the OpenDatabase method.

NOTE: If the number of records affected by the most recent Execute method in your current instance of Microsoft Access happens to be 2, the RecordsAffected property will return the correct number of records. Quit and restart Microsoft Access to ensure that you reproduce the desired results from this example.

1. Start Microsoft Access and open the sample database Northwind.mdb.

2. Create a module and type the following procedure:

         Sub WrongNum()
            Dim db As DATABASE
            Dim SPTErr As Error
            On Error GoTo WrongNum_err
            ' Substitute your own ODBC connection parameters.
            Set db = OpenDatabase("", False, False, _
               "ODBC;DSN=Pubs1;DATABASE=pubs;UID=sa;PWD=")
            ' Create a table in SQL Server and create a unique index.
            db.Execute "create table testrecs (f1 int)", dbSQLPassThrough
            db.Execute "create unique index idx on testrecs (f1)", _
               dbSQLPassThrough
   
            ' Insert two records.
            db.Execute "Insert into testrecs values(1)", dbSQLPassThrough
            db.Execute "Insert into testrecs values(2)", dbSQLPassThrough
   
            ' This message box returns 0 records.
            Msgbox db.RecordsAffected & " Records Affected."
   
            ' Delete the testrecs table.
            db.Execute "drop table testrecs", dbSQLPassThrough
   
            ' This message box returns 0 records.
            Msgbox db.RecordsAffected & " Records Affected."
          Exit Sub
            WrongNum_err:
            For Each SPTErr In DBEngine.Errors
               With SPTErr
                  Msgbox .Number & vbcr & .Description & vbcr & .Source
               End With
            Next SPTErr
         End Sub
   
   

3. To test this procedure, type the following line in the Debug window, and then press ENTER.

         WrongNum
   

   Note that a message box opens twice and displays the number 0 instead of the actual number of records affected, which is 2.

REFERENCES

For more information about the RecordsAffected property, search the Help Index for "RecordsAffected property."

Keywords          : kbusage ODBCSPT QryPass MdlQry
Version           : 7.0 97
Platform          : WINDOWS
Hardware          : x86
Issue type        : kbprb
Solution Type     : Info_Provided