How To Clear the Contents of a DBGrid Control

• Standard, Professional, and Enterprise Editions of Microsoft Visual Basic, 16-bit and 32-bit, for Windows, version 4.0

SUMMARY

This article describes how to clear the contents of a DBGrid control. A DBGrid control is bound to a Data control. To clear the DBGrid control of all data, set the RecordSource property of the Data control so no records are returned, and then execute the Refresh method on the Data control. The DBGrid control displays the data retrieved by the Data control.

MORE INFORMATION

The following instructions show how to create a sample program that demonstrates how to clear the DBGrid control. The form contains a DBGrid control bound to a Data control. The Data control is bound to the sample database shipping with Microsoft Visual Basic, BIBLIO.MDB, and the RecordSource is set to the Titles table. Two Command buttons are used to populate and clear the DBGrid control. To clear the DBGrid control, the RecordSource is set to a SQL statement that does not return any records. To populate the DBGrid control, the RecordSource property is set to the Titles table.

When you run the program, the DBGrid control is immediately populated because the RecordSource property of the Data control is bound to the Titles table. Click the Command button to clear the DBGrid control.

Follow these instructions to create a sample application that demonstrates this process:

1. Start Visual Basic version 4.0. If it is already running, from the File menu, select New Project.

2. Add a Data control, a DBGrid control, and two Command buttons to Form1.form.

3. Set the following properties for each control:

         Control          Default Name       Property           Value
         ---------------------------------------------------------------
   
         Data Control     Data1              DatabaseName     BIBLIO.MDB
                                             RecordSource     Title
   
         DBGrid Control   DBGrid1            DataSource       Data1
   
   

4. Copy the following code to the Code window of the Form1 form:

         Option Explicit
         Dim sql As String
   

         Private Sub Command2_Click()
            ' SQL statement that does not return records.
            sql = "SELECT * From Titles Where Title = Null"
            Data1.RecordSource = sql
            Data1.Refresh
            Command1.Visible = True
            Command2.Visible = False
         End Sub
   
         Private Sub Command1_Click()
         ' Set the RecordSource to fill the DBGrid control.
            Data1.RecordSource = "Titles"
            Data1.Refresh
            Command1.Visible = False
            Command2.Visible = True
         End Sub
   
         Private Sub Form_Load()
            Command1.Caption = "Fill DBGrid"
            Command1.Visible = False
            Command2.Caption = "Clear DBGrid"
            Command2.Visible = True
         End Sub
   
   

5. From the Run menu, select Start, or press the F5 key. Click the visible Command button to clear or populate the DBGrid control.