设置表A的DataColChanged事件:
if e.DataCol.Name = "某列" Then
Dim dr As DataRow = DataTables("表B").Find("某列 = '" & e.NewValue & "'")
if dr Isnot Nothing Then
e.Datarow("逻辑列") = True
Else
e.Datarow("逻辑列") = False
End If