PRB: CreateDynaset Err: Can't open any more tables or queries

- Standard and Professional Editions of Microsoft Visual Basic for

  Windows, version 3.0

SYMPTOMS

After using the CreateDynaset method several times to create a dynaset from the dynaset itself, you will receive this error:

   Can't open any more tables or queries.

CAUSE

The number of times a dynaset can be created from itself is limited in the current design of Visual Basic.

WORKAROUND

To work around the problem, base all sorts or filters off of a different dynaset. The following example illustrates this:

1. Start a new project in Visual Basic. Form1 is created by default.

2. Add a command button (Command1) and a text box (Text1) to the form.

3. Add the following code in the command click event.

      Sub Command1_Click()
         Dim db As Database
         Dim ds As Dynaset
         Dim ds2 As Dynaset
         Set db = OpenDatabase("C:\VB\BIBLIO.MDB")
         Set ds = db.CreateDynaset("SELECT * FROM Authors")
         Set ds2 = ds
         Do
            iCount = iCount + 1
            Text1.Text = iCount
            ds2.Sort = "Author"
            Set ds = ds2.CreateDynaset()
         Loop
      End Sub
   
   

4. Run the program or press the F5 key.

STATUS

This behavior is by design in Visual Basic version 3.0 for Windows. However, Microsoft is considering a change for future releases.

MORE INFORMATION

Steps to Reproduce Problem

1. Start a new project in Visual Basic. Form1 is created by default.

2. Add a command button (Command1) and a text box (Text1) to the form.

3. Add the following code in the Command1 click event:

      Sub Command1_Click()
         Dim db As Database
         Dim ds As Dynaset
         Set db = OpenDatabase("C:\VB\BIBLIO.MDB")
         Set ds = db.CreateDynaset("SELECT * FROM Authors")
         Do
            iCount = iCount + 1
            Text1.Text = iCount
            Set ds = ds.CreateDynaset()
         Loop
      End Sub
   
   

4. Run the code. The error should occur on the tenth iteration.