数据库的地址：D:\毕业设计\数据库\订单估算成本.mdb。段名为：产品单价。这是之前的程序，但是运行不了……求高手指教哈……
Private Sub Command1_Click()
Dim cn As ADODB.Connection
Dim rs1 As ADODB.Recordset
Dim tsql1 As String
Set cn = New ADODB.Connection
cn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\毕业设计\数据库\订单估算成本.mdb;Persist Security Info=False"
Set rs1 = New ADODB.Recordset
tsql1 = "select sum(产品单价)from 订单估算成本 where 车型 = Combo1.Textand 翻转机构 = Combo2.Text and 箱体材质 = Combo3.Text"
rs1.Open tsql1, cn, adOpenKeyset, adLockPessimistic
Text1.Text = rs1(0)
End Sub
