dbviewからのツリービューを最適化する

Question

以下は、データベースからツリービューにデータをロードするために使用したコードです。しかし、私はそれを取得している間に少し遅れているように感じる...それを最適化する方法はありますか？

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load 
    Try 
     If Not IsPostBack Then 
      PopulateRootLevel("0", "ALL") 
     End If 
    Catch ex As Exception 
     MSGMgr.errHandlerSys(ex.Message, lblMsg) 
    End Try 
End Sub 

Private Sub PopulateRootLevel(ByVal LvlCD As String, ByVal scheme As String) 

    Dim objConn As New SqlConnection(DBMgr.asyncADOCnnStr("SQL")) 

    Dim objCommand As SqlCommand 
    If scheme = "ALL" Then 
     objCommand = New SqlCommand("SELECT DISTINCT LevelCD, Level1 IsChecked, LevelCD+Level2+'|'+Level1+'|'+CASE WHEN Level3 IS NULL THEN '' ELSE Level3 END ID, Level3 Scheme, GroupNo, Descriptions Title, (SELECT DISTINCT COUNT(*) FROM i_Menu_Access WHERE GroupNo = prt.GroupNo and SubItemNo1='0' AND LevelCD='0' AND ItemNo <> '0') SubItemCnt FROM i_Menu_Access prt WHERE ItemNo = '0' AND LevelCD = '" & LvlCD & "' ORDER BY GroupNo", objConn) 
    Else 
     objCommand = New SqlCommand("SELECT DISTINCT LevelCD, Level1 IsChecked, LevelCD+Level2+'|'+Level1+'|'+CASE WHEN Level3 IS NULL THEN '' ELSE Level3 END ID, Level3 Scheme, GroupNo, Descriptions Title, (SELECT DISTINCT COUNT(*) FROM i_Menu_Access WHERE GroupNo = prt.GroupNo and SubItemNo1='0' AND LevelCD='0' AND ItemNo <> '0') SubItemCnt FROM i_Menu_Access prt WHERE ItemNo = '0' AND LevelCD = '" & LvlCD & "' AND Level3 = @Scheme ORDER BY GroupNo", objConn) 
     objCommand.Parameters.Add("@Scheme", SqlDbType.VarChar).Value = scheme 
    End If 

    Dim da As New SqlDataAdapter(objCommand) 
    Dim dt As New DataTable() 
    da.Fill(dt) 

    For Each dr As DataRow In dt.Rows 
     Dim child As New TreeNode() 
     child.Text = dr("Title").ToString().Trim() 
     child.Value = dr("ID").ToString().Trim() 

     Dim GrpNo As String = dr("GroupNo").ToString().Trim() 

     child.ToolTip = "Click to get Child" 
     child.SelectAction = TreeNodeSelectAction.SelectExpand 
     child.CollapseAll() 

     tvMenuTable.Nodes.Add(child) 
     PopulateSubLevel(GrpNo, LvlCD, child, scheme) 
    Next 

End Sub 

Private Sub PopulateSubLevel(ByVal parentid As Integer, ByVal LvlCD As String, ByVal parentNode As TreeNode, ByVal scheme As String) 

    Dim objConn As New SqlConnection(DBMgr.asyncADOCnnStr("SQL")) 

    Dim objCommand As SqlCommand 
    If scheme = "ALL" Then 
     objCommand = New SqlCommand("SELECT DISTINCT LevelCD, Level1 IsChecked, LevelCD+Level2+'|'+Level1+'|'+CASE WHEN Level3 IS NULL THEN '' ELSE Level3 END ID, Level3 Scheme, ItemNo, cast(groupno as varchar)+'|'+cast(itemno as varchar)+'|'+cast(subitemno1 as varchar) ID2, Descriptions Title, (SELECT DISTINCT COUNT(*) FROM i_Menu_Access WHERE GroupNo = prt.GroupNo AND ItemNo = prt.ItemNo AND SubItemNo1 <> '0' AND SubItemNo2 = '0' AND LevelCD = '0') SubItemCnt FROM i_Menu_Access prt WHERE LevelCD = @LvlCD AND GroupNo = @parentID AND ItemNo <> '0' AND SubItemNo1 = '0' ORDER BY ItemNo", objConn) 
     objCommand.Parameters.Add("@parentID", SqlDbType.Int).Value = parentid 
     objCommand.Parameters.Add("@LvlCD", SqlDbType.VarChar).Value = LvlCD 
    Else 
     objCommand = New SqlCommand("SELECT DISTINCT LevelCD, Level1 IsChecked, LevelCD+Level2+'|'+Level1+'|'+CASE WHEN Level3 IS NULL THEN '' ELSE Level3 END ID, Level3 Scheme, ItemNo, cast(groupno as varchar)+'|'+cast(itemno as varchar)+'|'+cast(subitemno1 as varchar) ID2, Descriptions Title, (SELECT DISTINCT COUNT(*) FROM i_Menu_Access WHERE GroupNo = prt.GroupNo AND ItemNo = prt.ItemNo AND SubItemNo1 <> '0' AND SubItemNo2 = '0' AND LevelCD = '0') SubItemCnt FROM i_Menu_Access prt WHERE LevelCD = @LvlCD AND GroupNo = @parentID AND ItemNo <> '0' AND SubItemNo1 = '0' AND Level3 = @Scheme ORDER BY ItemNo", objConn) 
     objCommand.Parameters.Add("@parentID", SqlDbType.Int).Value = parentid 
     objCommand.Parameters.Add("@LvlCD", SqlDbType.VarChar).Value = LvlCD 
     objCommand.Parameters.Add("@Scheme", SqlDbType.VarChar).Value = scheme 
    End If 

    Dim da As New SqlDataAdapter(objCommand) 
    Dim dt As New DataTable() 
    da.Fill(dt) 

    For Each dr As DataRow In dt.Rows 
     Dim child As New TreeNode() 
     child.Text = dr("Title").ToString().Trim() 
     child.Value = dr("ID").ToString().Trim() 

     Dim ID() As String 
     ID = dr("ID2").ToString().Trim().Split("|") 

     child.ToolTip = "Click to get Child" 
     child.SelectAction = TreeNodeSelectAction.SelectExpand 
     child.CollapseAll() 

     parentNode.ChildNodes.Add(child) 
     PopulateThirdLevel(ID(0), ID(1), LvlCD, child, scheme) 
    Next 

End Sub 

Private Sub PopulateThirdLevel(ByVal lvlOneID As Integer, ByVal lvlTwoID As Integer, ByVal LvlCD As String, ByVal parentNode As TreeNode, ByVal scheme As String) 

    Dim objConn As New SqlConnection(DBMgr.asyncADOCnnStr("SQL")) 

    Dim objCommand As SqlCommand 
    If scheme = "ALL" Then 
     objCommand = New SqlCommand("SELECT DISTINCT LevelCD, Level1 IsChecked, LevelCD+Level2+'|'+Level1+'|'+CASE WHEN Level3 IS NULL THEN '' ELSE Level3 END ID, Level3 Scheme, ItemNo, SubItemNo1, cast(groupno as varchar)+'|'+cast(itemno as varchar)+'|'+cast(subitemno1 as varchar) ID2, Descriptions Title FROM i_Menu_Access WHERE LevelCD = @LvlCD AND GroupNo = @lvlOneID AND ItemNo = @lvlTwoID AND ItemNo <> '0' AND SubItemNo1 <> '0' AND SubItemNo2 = '0' ORDER BY SubItemNo1", objConn) 
     objCommand.Parameters.Add("@lvlOneID", SqlDbType.Int).Value = lvlOneID 
     objCommand.Parameters.Add("@lvlTwoID", SqlDbType.Int).Value = lvlTwoID 
     objCommand.Parameters.Add("@LvlCD", SqlDbType.VarChar).Value = LvlCD 
    Else 
     objCommand = New SqlCommand("SELECT DISTINCT LevelCD, Level1 IsChecked, LevelCD+Level2+'|'+Level1+'|'+CASE WHEN Level3 IS NULL THEN '' ELSE Level3 END ID, Level3 Scheme, ItemNo, SubItemNo1, cast(groupno as varchar)+'|'+cast(itemno as varchar)+'|'+cast(subitemno1 as varchar) ID2, Descriptions Title FROM i_Menu_Access WHERE LevelCD = @LvlCD AND GroupNo = @lvlOneID AND ItemNo = @lvlTwoID AND ItemNo <> '0' AND SubItemNo1 <> '0' AND SubItemNo2 = '0' AND Level3 = @Scheme ORDER BY SubItemNo1", objConn) 
     objCommand.Parameters.Add("@lvlOneID", SqlDbType.Int).Value = lvlOneID 
     objCommand.Parameters.Add("@lvlTwoID", SqlDbType.Int).Value = lvlTwoID 
     objCommand.Parameters.Add("@LvlCD", SqlDbType.VarChar).Value = LvlCD 
     objCommand.Parameters.Add("@Scheme", SqlDbType.VarChar).Value = scheme 
    End If 

    Dim da As New SqlDataAdapter(objCommand) 
    Dim dt As New DataTable() 
    da.Fill(dt) 

    For Each dr As DataRow In dt.Rows 
     Dim child As New TreeNode() 
     child.Text = dr("Title").ToString().Trim() 
     child.Value = dr("ID").ToString().Trim() 

     Dim ID() As String 
     ID = dr("ID2").ToString().Trim().Split("|") 

     child.SelectAction = TreeNodeSelectAction.SelectExpand 
     child.CollapseAll() 

     parentNode.ChildNodes.Add(child) 
     Populate4thLevel(ID(0), ID(1), ID(2), LvlCD, child, scheme) 
    Next 
End Sub 

Private Sub Populate4thLevel(ByVal lvlOneID As Integer, ByVal lvlTwoID As Integer, ByVal lvl3rdID As Integer, ByVal LvlCD As String, ByVal parentNode As TreeNode, ByVal scheme As String) 

    Dim objConn As New SqlConnection(DBMgr.asyncADOCnnStr("SQL")) 

    Dim objCommand As SqlCommand 
    If scheme = "ALL" Then 
     objCommand = New SqlCommand("SELECT DISTINCT LevelCD, Level1 IsChecked, LevelCD+Level2+'|'+Level1+'|'+CASE WHEN Level3 IS NULL THEN '' ELSE Level3 END ID, Level3 Scheme, ItemNo, SubItemNo2, Descriptions Title FROM i_Menu_Access WHERE LevelCD = @LvlCD AND GroupNo = @lvlOneID AND ItemNo = @lvlTwoID AND SubItemNo1 = @lvl3rdID AND SubItemNo2 <> '0' ORDER BY SubItemNo2", objConn) 
     objCommand.Parameters.Add("@lvlOneID", SqlDbType.Int).Value = lvlOneID 
     objCommand.Parameters.Add("@lvlTwoID", SqlDbType.Int).Value = lvlTwoID 
     objCommand.Parameters.Add("@lvl3rdID", SqlDbType.Int).Value = lvl3rdID 
     objCommand.Parameters.Add("@LvlCD", SqlDbType.VarChar).Value = LvlCD 
    Else 
     objCommand = New SqlCommand("SELECT DISTINCT LevelCD, Level1 IsChecked, LevelCD+Level2+'|'+Level1+'|'+CASE WHEN Level3 IS NULL THEN '' ELSE Level3 END ID, Level3 Scheme, ItemNo, SubItemNo2, Descriptions Title FROM i_Menu_Access WHERE LevelCD = @LvlCD AND GroupNo = @lvlOneID AND ItemNo = @lvlTwoID AND SubItemNo1 = @lvl3rdID AND SubItemNo2 <> '0' AND Level3 = @Scheme ORDER BY SubItemNo2", objConn) 
     objCommand.Parameters.Add("@lvlOneID", SqlDbType.Int).Value = lvlOneID 
     objCommand.Parameters.Add("@lvlTwoID", SqlDbType.Int).Value = lvlTwoID 
     objCommand.Parameters.Add("@lvl3rdID", SqlDbType.Int).Value = lvl3rdID 
     objCommand.Parameters.Add("@LvlCD", SqlDbType.VarChar).Value = LvlCD 
     objCommand.Parameters.Add("@Scheme", SqlDbType.VarChar).Value = scheme 
    End If 

    Dim da As New SqlDataAdapter(objCommand) 
    Dim dt As New DataTable() 
    da.Fill(dt) 

    For Each dr As DataRow In dt.Rows 
     Dim child As New TreeNode() 
     child.Text = dr("Title").ToString().Trim() 
     child.Value = dr("ID").ToString().Trim() 

     child.SelectAction = TreeNodeSelectAction.SelectExpand 
     child.CollapseAll() 

     parentNode.ChildNodes.Add(child) 
    Next 
End Sub 

Answer 1

さて、あなたは正しくデータ・ベースを設計した場合、あなたはどのレベルで&フィルノードを取得するために一つだけの機能が必要になります。たとえば、のは、そのような私たちは同じItems表とParentIdにFKを入れているし、それがルートレベルの項目を示すNULL可能

ItemId int NOT NULL PK 
ItemText varchar(200) 
ParentId int NULL FK 

注意として「アイテム」サンプルデータベースのテーブルを考えてみましょう。さて、あなたは、ルートレベルの項目を取得したい場合には、そのような

SELECT ItemId, ItemText, ParentId FROM Items WHERE ParentId = @ParentId 

としてクエリを使用して任意のレベルでアイテムを入手することができ、NULLとして@ParentIdを渡す - 任意のノードを展開し、チャイルズを取得し、ParentIdとしてそのノードのItemIdを渡します上記のクエリへ。

Answer 2

データセットにデータテーブルを追加し、データセットで親子関係を設定することができます。

完全でクリーンで最適化されたコードです。私は必要に応じてコメントを書いた。

DataTable dtbl1=new DataTable();//parent datatable 
DataTable dtbl2=new DataTable();//child datatable 

DataSet ds = new DataSet(); 
ds.Tables.Add(dtbl1); 
ds.Tables.Add(dtbl2); 
ds.Relations.Add("Children", dtbl1.Columns["dtb1ID"], dtbl2.Columns["dtbl2ID"]);//define parent child relation in dataset 

if (ds.Tables[0].Rows.Count > 0) 
{ 
    trv.Nodes.Clear(); 
    Int32 count = 0; 

    foreach(DataRow masterRow in ds.Tables[0].Rows) 
    { 
     TreeNode masterNode = new TreeNode((String)masterRow["dtbl1ColumnYouWantToDisplay"], Convert.ToString(masterRow["dtbl1ID"])); 
     trv.Nodes.Add(masterNode); 

     foreach (DataRow childRow in masterRow.GetChildRows("Children")) 
     { 
      TreeNode childNode = new TreeNode((String)childRow["dtbl2ColumnYouWantToDisplay"], Convert.ToString(childRow["dtb2ID"])); 
      masterNode.ChildNodes.Add(childNode); 
      count++; 
     } 
    } 
    trv.ExpandAll(); 
}