Tai MDIForm Private Sub MDIForm_Load() cn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + App.Path + "\qlxm.mdb;Persist Security Info=False" cn.CursorLocation = adUseClient End Sub Private Sub mnintatcacachang_Click() ' khai bao recordset Dim rs As New ADODB.Recordset ' lay ve tat ca cac hang rs.Open "hang", cn ' dua du lieu vao Rhang Set Rhang.DataSource = rs Rhang.Show ' hien thi Rhang End Sub Private Sub mnintatcacacxe_Click() ' khai bao recordset Dim rs As New ADODB.Recordset ' lay ve tat ca cac hang rs.Open "xemay", cn ' dua du lieu vao Rxemay Set RXemay.DataSource = rs RXemay.Show End Sub Private Sub mntimgiavain_Click() frmtimgia.Show End Sub Private Sub mntkvain_Click() frmtimhang.Show End Sub Tai Form tim gia Dim rs As New ADODB.Recordset Private Sub cmdtk_Click() Dim rs As New ADODB.Recordset rs.Open "select*from xemay where gia>=" + txttu.Text + "and gia<=" + txtden.Text, cn Set DataGrid1.DataSource = rs End Sub Private Sub Form_Load() If rs.State = adStateOpen Then rs.Close End If rs.Open "select*from xemay", cn, 2, 3 Set DataGrid1.DataSource = rs End Sub Private Sub cmdluu_Click() Private Sub cmdphuchoi_Click() rs.Requery rs.CancelBatch adAffectCurrent DataGrid1.AllowAddNew = False End Sub DataGrid1.AllowUpdate = False DataGrid1.AllowArrows = False End Sub Private Sub cmdsua_Click() DataGrid1.AllowUpdate = True End Sub Private Sub cmdthem_Click() DataGrid1.AllowAddNew = True DataGrid1.AllowUpdate = True DataGrid1.AllowArrows = True Datagrid1.refresh End Sub Private Sub cmdxoa_Click() t = MsgBox("chac chac xoa xong", vbYesNo) If t = vbYes Then rs.Delete End If End Sub Private Sub cmdIn_Click() Dim rs As New ADODB.Recordset rs.Open "select*from xemay where gia>=" + txttu.Text + "and gia<=" + txtden.Text, cn Set RXemay.DataSource = rs RXemay.Show End Sub Tai Form tim hang Dim rs As New ADODB.Recordset Private Sub cmdIn_Click() Dim rs As New ADODB.Recordset rs.Open "select*from hang,xemay where hang.mahang=xemay.mahang and tenhang like '%" + txttk.Text + "%' ", cn Set RXemay.DataSource = rs RXemay.Show End Sub Private Sub Form_Load() If rs.State = adStateOpen Then rs.Close End If rs.Open "select*from xemay", cn, 2, 3 Set DataGrid1.DataSource = rs End Sub Private Sub txttk_Change() Dim rs As New ADODB.Recordset rs.Open "select*from hang,xemay where hang.mahang=xemay.mahang and tenhang like '%" + txttk.Text + "%' ", cn Set DataGrid1.DataSource = rs End Sub Tại formtimmax Private Sub Form_Load() Dim rs As New ADODB.Recordset rs.Open "xemay", cn Dim tenxe, tenxemin As String Max = 0: Min = 0: dem = 0 If Not rs.EOF Then Min = rs.Fields("gia") End If Do While Not rs.EOF() If Max < rs.Fields("gia") Then Max = rs.Fields("gia") tenxe = rs.Fields("tenxe") End If If Min > rs.Fields("gia") Then Min = rs.Fields("gia") tenxemin = rs.Fields("tenxe") End If dem = dem + rs.Fields("soluong") rs.MoveNext Loop txtcn.Text = tenxe Txttong.Text = dem txttn.Text = tenxemin End Sub Tại form đếm c¸c h·ng xe(phải kết nối query trªn asscer) Private Sub Form_Load() Dim rs As New ADODB.Recordset rs.Open "tk2", cn Set DataGrid1.DataSource = rs End Sub . Private Sub cmdxoa_Click() t = MsgBox("chac chac xoa xong", vbYesNo) If t = vbYes Then rs.Delete End If End Sub Private Sub cmdIn_Click() Dim rs