查询问题

Question

执行此查询时：

Dim Var
Var = ("select max(Autonumber) from tblAutonumber")
DoCmd.RunSQL (Var)

我将var的值设为"select max(Autonumber) from tblAutonumber"，而不是我要查找的最大值。

代码：

Private Sub btnSubmit_Enter()
DoCmd.RunSQL ("insert into tblAutonumber (Dummy)values ('DummyValue')")

Dim db As DAO.Database
Dim rst As DAO.Recordset
Dim strMaxNum As String
Dim strSQL As String

strSQL = "select max(Autonumber) as maxNum from tblAutonumber"
Set db = CurrentDb
Set rst = db.OpenRecordset(strSQL)

 rst.MoveFirst
 strMaxNum = rst!maxNum
'Dim Var As Variant
'Var = "select max(Autonumber) from tblAutonumber"
'DoCmd.RunSQL (Var)
txtAutoNumber.Value = strSQL
DoCmd.RunSQL ("insert into tbltesting (Empid,TestScenario,owner,event,version,expresult,variation,status,homestore)values ('" & Me.txtEmpNo.Value & "','" & Me.txtTestScenario.Value & "','" & Me.txtOwner.Value & "','" & Me.txtEvent.Value & "', '" & Me.txtVersion.Value & "','" & Me.txtExpectedResult.Value & "', '" & Me.txtVariation.Value & "', '" & Me.txtStatus.Value & "','" & Me.txtHomeStore.Value & "')")
'DoCmd.RunSQL ("INSERT INTO tblContract(testid)select max(testid) FROM tbltesting")
 DoCmd.RunSQL ("insert into tblContract (Empid,testid,Start1,Finish1,Store1,Start2,Finish2,Store2 )values ('" & Me.txtEmpNo.Value & "','" & Me.txtAutoNumber.Value & "','" & Me.txtContSunStart1.Value & "', '" & Me.txtContSunFinish1.Value & "','" & Me.txtContSunStore1.Value & "','" & Me.txtContSunStart2.Value & "', '" & Me.txtContSunFinish2.Value & "','" & Me.txtContSunStore2.Value & "')")
 'DoCmd.RunSQL = "INSERT INTO tblContract (Empid,testid, Start1, Finish1, Store1, Start2, Finish2, Store2)  SELECT " & Me.txtEmpNo.Value & "', MAX(testid), '" & Me.txtContSunStart1.Value & "', '" & Me.txtContSunFinish1.Value & "','" & Me.txtContSunStore1.Value & "','" & Me.txtContSunStart2.Value & "', '" & Me.txtContSunFinish2.Value & "','" & Me.txtContSunStore2.Value & "' " & "FROM tbltesting'"
'DoCmd.RunSQL = "INSERT INTO tblContract (Empid,testid, Start1, Finish1, Store1, Start2, Finish2, Store2)  SELECT " & Me.txtEmpNo.Value & "', MAX(testid), '" & Me.txtContSunStart1.Value & "', '" & Me.txtContSunFinish1.Value & "','" & Me.txtContSunStore1.Value & "','" & Me.txtContSunStart2.Value & "', '" & Me.txtContSunFinish2.Value & "','" & Me.txtContSunStore2.Value & "' " & "FROM tbltesting'"
End Sub

Answer 1

对于您要完成的任务，您可能只想使用DMAX域聚合函数，该函数将返回给定域（即表）的最大表达式（即列）。这是一个例子：

  Dim lastAutonumber As Long
  lastAutonumber = DMax("Autonumber", "tblAutonumber")

Answer 2

正如Rich所评论的那样：

Dim Var 
Var = "select max(Autonumber) from tblAutonumber"
DoCmd.RunSQL (Var)

Answer 3

使用Access UI：

Dim Var As Long
var = CurrentProject.Connection.Execute("select max(Autonumber) from tblAutonumber;")(0)