Microsoft KB Archive/149092

= How To Add Records and Edit Data in a DBGrid Cell =

Article ID: 149092

Article Last Modified on 6/29/2004

-

APPLIES TO


 * Microsoft Visual Basic 4.0 Standard Edition
 * Microsoft Visual Basic 4.0 Professional Edition
 * Microsoft Visual Basic 4.0 Professional Edition
 * Microsoft Visual Basic 4.0 16-bit Enterprise Edition
 * Microsoft Visual Basic 4.0 32-Bit Enterprise Edition

-



This article was previously published under Q149092



SUMMARY
This article describes how to programmatically edit the data and add new records to a DBGrid control. You can change the contents of a cell and those changes will appear on the screen, but they are not written to the data source bound to the DBGrid control. To write these changes to the data source, you must instead edit the underlying recordset.



MORE INFORMATION
The following example creates a simple database containing one table with four fields and five records. Each record is a number in the field. The database is going to be the data source.

When you click on a cell, the data in that cell is shown in a TextBox. When you change the contents of that cell, the changes are shown on the DBGrid control. However, when you execute the UpdateControls method through a command button, the changes disappear from the cell, indicating the data source was not updated.

You must click the Update Recordset button when you make your changes in the TextBox to ensure that the changes are written to the data source. The Update Recordset button updates the underlying recordset of the Data control. Since the DBGrid control is bound to the Data control, the changes appear in the DBGrid control.

Creating the Sample Application
The following sample application demonstrates how to edit the contents of a DBGrid cell:

  Start Visual Basic. Once it is running, on the File menu, click New Project. Add a Data control, a DBGrid control, a TextBox, and three Command buttons. Set the following properties for each control:   Control       Default Name       Property       Value -

DBGrid       DBGrid1            DataSource     Data1

  Copy the following code sample to the Form1 code window: Option Explicit Dim rs1 As Recordset Dim db As Database Dim td As TableDef Dim fl As Field Dim igRow As Integer, igColumn As Integer Dim iFields As Integer, iRecords As Integer Dim vargBookmark As Variant

Private Sub Command1_Click ' The Create Database button: By clicking this button, you create ' a database with four fields and five records.

Set db = CreateDatabase("C:\test.mdb", dbLangGeneral) Set td = db.CreateTableDef("Table1")

' After you create the database, you need to add fields to it. For iFields = 1 To 4 ' The last number can be changed to the ' number of fields you want in the database. Set fl = td.CreateField("Field " & CStr(iFields), dbText) td.Fields.Append fl        Next iFields

db.TableDefs.Append td

' Now that you have added fields to the database, you need to add ' some records through a recordset. Set rs1 = db.OpenRecordset("Table1", dbOpenTable) For iRecords = 1 To 5 'For each row rs1.AddNew         'Add a new record

For iFields = 1 To 4       ' For each field in the record, add rs1("Field " & CStr(iFields)) = CStr(iFields) ' a number. Next iFields

rs1.Update Next iRecords

' Close both the recordset and database. rs1.Close db.Close

' Populate the DBGrid control with the contents of the Recordset. Set db = OpenDatabase("C:\test.mdb") Set rs1 = db.OpenRecordset("Select * from Table1") Set Data1.Recordset = rs1

Command1.Visible = False Command2.Visible = True Command4.Visible = True End Sub

Private Sub Command2_Click ' The Update Database button: By clicking this button, you save ' the contents of the text box to the database. Since the contents ' of the recordset are being modified, the contents are saved to        ' the database after you execute the Update method.

Data1.Recordset.Edit Data1.Recordset.Fields(igColumn) = Text1.Text Data1.Recordset.Update End Sub

Private Sub Command3_Click ' The Update DBGrid button: By clicking this button, you execute ' the UpdateControls method on the Data control to demonstrate ' that changing the cell in a bound DBGrid control does not save ' the new information to the database. To save these changes, you ' must modify the underlying recordset from the Data control.

Data1.UpdateControls End Sub

Private Sub Command4_Click ' The Add New Record button: By clicking this button, you add new ' records to the recordset. Use the following code to add a new ' record to the DBGrid control.

' Set DBGrid and Data Control Properties to allow new records to        ' be added. DBGrid1.AllowAddNew = True Data1.EOFAction = vbAddNew Data1.Recordset.MoveLast Data1.Recordset.MoveNext DBGrid1.Row = DBGrid1.VisibleRows - 1 Data1.Recordset.AddNew For iFields = 1 To 4   ' For each field in the record, ' add the contents of the text box. Data1.Recordset("Field " & CStr(iFields)) = Text1.Text Next iFields Data1.Recordset.Update

End Sub

Private Sub DBGrid1_Change Command3.Visible = True End Sub

Private Sub DBGrid1_MouseUp(Button As Integer, Shift As Integer, _                                 X As Single, Y As Single) Command2.Visible = True igColumn = DBGrid1.ColContaining(X) igRow = DBGrid1.RowContaining(Y) vargBookmark = DBGrid1.RowBookmark(igRow)

Text1.Text = DBGrid1.Columns(igColumn).CellValue(vargBookmark)

End Sub

Private Sub Form_Load Command1.Visible = False Command2.Visible = False Command3.Visible = False Command4.Visible = False Command1.Caption = "Create Database" Command2.Caption = "Update Database" Command3.Caption = "Update DBGrid" Command4.Caption = "Add New Record"

' If the database does not exist, show the Create Database button. If Dir("C:\test.mdb") = "" Then Command1.Visible = True Else ' Open an existing database. Set db = OpenDatabase("C:\test.mdb") Set rs1 = db.OpenRecordset("Select * from Table1") Set Data1.Recordset = rs1 Command4.Visible = True End If

End Sub

Private Sub Text1_Change Command2.Visible = True End Sub



Running the Sample Application

 * 1) On the Run menu, click Start, or press F5.
 * 2) Click on a cell on the DBGrid control and change the contents of that cell. Click the Update DBGrid button. Note that your changes disappear from the DBGrid. Clicking on a blank area on the DBGrid control gives error 6148 - Invalid row number.
 * 3) Click on a cell. Note that the contents of the cell appear on the TextBox. Change the contents of the TextBox and then click the Update Recordset button. Note that your changes now appear on the DBGrid control.
 * 4) Click the Add New Records button to add a new record to the DBGrid control. The contents of the text box will be added as a new record.

Keywords: kbhowto kbctrl kbcode KB149092

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.