如何使用多个组合框来过滤数据

Question

有人可以请帮我解决这个问题我是一个初学者编程。

有两个组合框是S.Y.（学年）和Sem（学期），我想用这两个组合框在下面的列表视图中有更具体的数据。

Private Sub Search_Record() 
    Dim conn As New OleDbConnection 
    Dim cmd As New OleDbCommand 
    Dim da As New OleDbDataAdapter 
    Dim dt As New DataTable 
    Dim sSQL As String = String.Empty 


    Try 

     conn = New OleDbConnection(Get_Constring) 
     conn.Open() 
     cmd.Connection = conn 
     cmd.CommandType = CommandType.Text 
     sSQL = "SELECT edp_number, LastName + ', ' + FirstName as name, course as course, Address as address, syear as syear, Sem as sem FROM tblStudent" 
     If Me.cboSearchBy.Text = "1st" Then 
      sSQL = sSQL & " where Sem like '1st" & Me.txtSearch.Text & "%'" 
     Else 
      sSQL = sSQL & " where Sem like '2nd" & Me.txtSearch.Text & "%'" 
     End If 
     cmd.CommandText = sSQL 
     da.SelectCommand = cmd 
     da.Fill(dt) 

     Me.dtgResult.DataSource = dt 
     If dt.Rows.Count = 0 Then 
      MsgBox("No record found!") 
     End If 

    Catch ex As Exception 
     MsgBox(ErrorToString) 
    Finally 
     conn.Close() 
    End Try 
End Sub 

这个代码仅使用SEM组合框是cboSearchby所以现在我需要知道的是如何使组合框S.Y运作也是一样，如果还使用texbox搜索名字和姓氏。

Answer 1

，你只需要在你的if语句添加另一个条件：

If Me.cboSearchBy.Text = "1st" and Me.cboSY.Text = "2014-2015" Then 
    sSQL = sSQL & " where Sem like '1st" & Me.txtSearch.Text & "%' and SY like '" & Me.cboSY.Text & "%' " 
Else 
    sSQL = sSQL & " where Sem like '2nd" & Me.txtSearch.Text & "%' and SY like '" & Me.cboSY.Text & "%' " 
End If 

然后如果你想添加的搜索的姓氏和名字，只是添加的if语句的另一个条件。

注意：在使用逻辑运算符，如果所有条件为真，而或为真，如果条件ATLEAST之一为真和是真实的。