主题：求：SQL语句筛选，如何用变量代替查询列，查询符，查询值

大概如此:

Dim t As Table=Tables( e.Form.name & "_table1")

Dim ct1,ct2,ct3,sql,str1, str2 As String

With e.Form

    ct1 = .Controls("ComboBox1").value

    ct2 = .Controls("ComboBox2").value

    ct3 = .Controls("ComboBox3").value

End With

For Each dc As DataCol In DataTables("订单").DataCols

    If dc.IsString Then

        str1+="," & dc.Name

    ElseIf dc.IsDate Then

        str2+="," & dc.Name

    End If

Next

sql= ct1 & " " & ct2 &  sql & " group by 产品,客户,雇员,单价,数量"

sql = "Select distinct Max(日期) As 日期,产品,客户,雇员  ,单价,数量 from {订单} where " & sql

Dim cmd As New SQLCommand

cmd.CommandText = sql

t.DataSource = cmd.ExecuteReader

...........

............

注:如"%"不行請自行換為"*",我是"*"不行才換為"%"

利用DataType.Name还可以简化:

Dim t As Table=Tables( e.Form.name & "_table1")

Dim Lm,Bjf,Bjz,sql,str As String

With e.Form

    Lm= .Controls("ComboBox1").value

    Bjf= .Controls("ComboBox2").value

    Bjz = .Controls("ComboBox3").value

End With

str = DataTables("订单").DataCols(Lm).DataType.Name

If Str =  "String" Then

    if  Bjf.Contains("like") Then

        sql = " ' %" & Bjz & "%'"

    else

         sql = " '" & Bjz & "'"

     End if

ElseIf Str = "DateTime" Then

      sql = " #" & Bjz & "#"

Else

      sql = " " & Bjz

End If

sql= Lm & " " & Bjf &  sql & " group by 产品,客户,雇员,单价,数量"

sql = "Select distinct Max(日期) As 日期,产品,客户,雇员  ,单价,数量 from {订单} where " & sql

Dim cmd As New SQLCommand

cmd.CommandText = sql

t.DataSource = cmd.ExecuteReader