PRB: RDC Refresh Method Failure with Bound DBListbox

• Enterprise Edition of Microsoft Visual Basic, 32-bit only, for Windows, version 4.0

SYMPTOMS

If you change the SQL Property of a Remote Data Control with a bound DBListbox at run time, the refresh method doesn't show the changes in the DBListbox as it does for other controls. The Refresh method must be called twice.

RESOLUTION

Refresh the remote data control twice. Replace the Command1_Click in the previous sample with the code below:

   Private Sub Command1_Click()
     ' Restrict the SQL to display only the authors whose last name
     ' start with an R
     MSRDC1.SQL = "SELECT * FROM Authors WHERE AU_Lname LIKE'R%'"
     MSRDC1.Refresh
     MSRDC1.Refresh
   End Sub

STATUS

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Problem

1. Create a new ODBC data source for SQL Server called "RefreshTest" using the "32-bit ODBC" section of the Control Panel. Set the database name to the "Pubs" Database.

2. Start a new Visual Basic Project. Form1 is created by default.

3. Add the following controls to Form1 and give them the properties indicated:

         Default Name             Caption            Name
         --------------------   -----------------  ----------
         Remote Data Control      Authors            MSRDC1
         Command1                 Change SQL         Command1
         DBList                   Not Applicable     DBList1
   
   

4. Set the DBList Control RowSource property to MSRDC1.

5. Add the following code to the General Declarations section of Form1:

   Option Explicit

      Private Sub Form_Load()
        MSRDC1.DataSourceName = "RefreshTest"
        MSRDC1.SQL = "Select * from Authors"
        MSRDC1.Refresh
        DBList1.ListField = "Phone"
      End Sub
   
      Private Sub Command1_Click()
        ' Restrict the SQL to display only the authors whose last name
        ' start with an R
        MSRDC1.SQL = "SELECT * FROM Authors WHERE AU_Lname LIKE'R%'"
        MSRDC1.Refresh
      End Sub
   
   

6. Press the F5 key to run the project. The DBListbox will contain many rows of data.

7. Click the Command button "Change SQL," and note that the DBListbox doesn't change to reflect the new SQL.

REFERENCES

Building Client / Server Applications with Visual Basic Chapter 11.