How to update the value of a database record in VB

How does VB modify the value recorded in the database

In the method of the Taoist friend upstairs:

sSQL="update table set field=20"

should be changed to:

sSQL=＂update table set field1=20,...,field2=20 where id=3＂

But if there is no record 3 in your database, an error will occur.

There is another way to use recordset to process:

dim cn as new adodb.connection

dim rs as new adodb.recordset

rs.open "select * from database where id=3",adOpenDynamic, adLockOptimistic, -1

if not rs.eof then

rs("Field 1 you want to modify")="Specific value 1"

...

rs（＂Field n＂you want to modify）=＂Specific value n＂

rs.update

end if

rs.close

I usually do this when designing. Although it is more troublesome, it is basically error-free. Also, it is best to add an ID when designing the database, so as to ensure the uniqueness of the data.

VB Access database modification

Private Sub Command1_Click() 'Borrow book'

Dim jc As Boolean

jc = False

Adodc1.Recordset.MoveFirst

For i = 1 To Adodc1.Recordset.RecordCount

If Text1.Text = Adodc1.Recordset.Fields(1).Value And Adodc1.Recordset.Fields(4).Value = True Then

Adodc1.Recordset.Fields(4).Value = Not Adodc1.Recordset.Fields(4).Value

Adodc1.Recordset.Update

jc = True

End If

Adodc1.Recordset.MoveNext

Next i

If jc Then MsgBox ＂Borrowing successful＂ Else MsgBox ＂The book has been borrowed or the book does not exist＂

End Sub

Private Sub Command2_Click() 'Return the book'

Dim hs As Boolean

hs = False

Adodc1.Recordset.MoveFirst

For i = 1 To Adodc1.Recordset.RecordCount

If Text1.Text = Adodc1.Recordset.Fields(1).Value And Adodc1.Recordset.Fields(4).Value = False Then

Adodc1.Recordset.Fields(4).Value = Not Adodc1.Recordset.Fields(4).Value

Adodc1.Recordset.Update

jc = True

End If

Adodc1.Recordset.MoveNext

Next i

If jc Then MsgBox ＂Return successful＂ Else MsgBox ＂The book is already in the library or the book does not exist＂

End Sub

Private Sub Form_Load()

Text1.Text = "＂"

Adodc1.Visible = False

Adodc1.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=＂ & App.Path & "\mybook.mdb;Persist Security Info =false＂"

Adodc1.CommandType = adCmdText

Adodc1.RecordSource = "select * from book"

Adodc1.Refresh

End Sub

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