Controlling Transactions (ADO)
ADO supports transaction processing within a connection with the help of the BeginTrans, CommitTrans, and RollbackTrans methods on a Connection object. The general idea of implementing transaction processing in ADO is illustrated in the following simple code snippet.
Const DS = "MySqlServer"
Const DB = "Northwind"
Const DP = "SQLOLEDB"
Dim oConn As ADODB.Connection
Dim oRs As ADODB.Recordset
Dim sConn As String
sConn = "Provider=" & DP & _
";Data Source=" & DS & _
";Initial Catalog=" & DB & _
";Integrated Security=SSPI;"
sSQL = "SELECT ProductID, ProductName FROM Products"
Set oConn = New ADODB.Connection
oConn.Open sConn
' Create and Open the Recordset object.
Set oRs = New ADODB.Recordset
oRs.Open sSQL, oConn, adOpenStatic, adLockOptimistic, adCmdText
If oRs.RecordCount > 1 Then
oRs.MoveFirst
Id1 = oRs("ProductID")
Name1 = oRs("ProductName")
oRs.MoveNext
Id2 = oRs("ProductID")
Name2 = oRs("ProductName")
q = "Switch ID's of " & Name1 & " and " & Name2 & "?"
If MsgBox(q, vbYesNo) = vbYes Then
oRs.MoveFirst
oRs("ProductName") = Name2
oRs.Update
oRs.MoveNext
oRs("ProductName") = Name1
oRs.Update
If MsgBox("Save changes?", vbYesNo) = vbYes Then
Else
End If
End If
End If
oRs.Close
oConn.Close
Here transaction processing is used to ensure that the two records are updated as one unit of operation, and that the two product names are either interchanged or not changed at all.
For detailed discussions of transaction processing see Updating and Persisting Data.