简单问题帮帮忙,马上结帐

Question

        Dim strCmddetail As String
        If cmdCode = 3401 Then
            strCmddetail = cmdCode & ":张三"
        ElseIf cmdCode = 3402 Then
            strCmddetail = cmdCode & ":李四"
        Else
            strCmddetail = strCmdNo
        End IfcmdCode 为3401,3402都好好的,为什么当cmdCode ="" 时就出错?
该怎么改?下面是insert语句,把strCmddetail值插进去

Answer 1

因为cmdCode是数字类型,而""又不能隐式转换成数字类型.

Answer 2

Dim strCmddetail As String
if string.IsNullOrEmpty(cmdCode) then
strCmddetail = strCmdNo
else
        If cmdCode = 3401 Then
            strCmddetail = cmdCode & ":张三"
        ElseIf cmdCode = 3402 Then
            strCmddetail = cmdCode & ":李四"
         End If
end if

Answer 3

string.IsNullOrEmpty在2003里没有,那该换成什么??

Answer 4

if cmdCode is dbnull.value then
  strCmddetail = strCmdNo
else
        If cmdCode = 3401 Then
            strCmddetail = cmdCode & ":张三"
        ElseIf cmdCode = 3402 Then
            strCmddetail = cmdCode & ":李四"
         End If
end if

Answer 5

Dim strCmddetail As String
        If cmdCode = 3401 Then
            strCmddetail = cmdCode & ":张三"
        ElseIf cmdCode = 3402 Then
            strCmddetail = cmdCode & ":李四"
        ElseIf (cmdCode = "" || cmdCode = null) 
            strCmddetail = strCmdNo & ""
        End If