RadTreview conected to DB example

It is very easy to work with treeviews and DB. The table structure is one of the most important things to take into consideration (It must be a table that has recursivity). Let's see a small example.

Description:
This treeview will show the available menu options for an application. Normally it varies depending on the environment:DEV(1), TEST(2), PRODUCTION(3). However, for this small example we are just sending 1 (Dev environment) hardcoded. You could use a combobox and send its value.

1) The table:
1 CREATE TABLE [dbo].[Metal_Menu](
2 [ME_SEQ] [uniqueidentifier] ROWGUIDCOL NOT NULL CONSTRAINT [DF_Metal_Menu_ME_SEQ] DEFAULT (newid()),
3 [ME_PARENT] [uniqueidentifier] NULL,
4 [ME_DESC] [varchar](100) NULL,
5 [ME_URL] [varchar](500) NULL,
6 [ME_PAGE] [varchar](100) NULL,
7 [ME_TYPE] [int] NULL,
8 [Active] [bit] NULL CONSTRAINT [DF_Metal_Menu_Active] DEFAULT ((1)),
9 [CreatedBY] [varchar](255) NULL CONSTRAINT [DF_Metal_Menu_CreatedBY] DEFAULT ('web\iuser'),
10 [CreatedDate] [datetime] NULL CONSTRAINT [DF_Metal_Menu_CreatedDate] DEFAULT (getdate()),
11 [ModifBy] [varchar](255) NULL CONSTRAINT [DF_Metal_Menu_ModifBy] DEFAULT ('web\iuser'),
12 [ModifDate] [datetime] NULL CONSTRAINT [DF_Metal_Menu_ModifDate] DEFAULT (getdate()),
13 CONSTRAINT [PK_Metal_Menu] PRIMARY KEY CLUSTERED
14 (
15 [ME_SEQ] ASC
16 )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
17 ) ON [PRIMARY]


2. The HTML portion of the RADTREEVIEW:

1 <telerik:RadTreeView ID="rtvFrom" runat="server" EnableDragAndDrop="True" OnNodeDrop="RadTreeView1_HandleDrop"
2 OnClientNodeDropping="onNodeDropping" OnClientNodeDragging="onNodeDragging" MultipleSelect="true" EnableDragAndDropBetweenNodes="true" CheckBoxes="false">
3 <DataBindings>
4 <telerik:RadTreeNodeBinding Expanded="True" AllowDrop="false"/>
5 </DataBindings>
6 </telerik:RadTreeView>


3. The code behind (VB.Net) for this radtreeview:


1 rtvFrom.Nodes.Clear()
2 rtvFrom.DataTextField = "SYME_DESC"
3 rtvFrom.DataFieldID = "SYME_SEQ"
4 rtvFrom.DataValueField = "SYME_SEQ"
5 rtvFrom.DataFieldParentID = "SYME_PARENT"
6 ViewState.Add("TreeFrom", GetMenuTreeSync(1, strUser))
7 rtvFrom.DataSource = CType(ViewState("TreeFrom"), Data.DataSet)
8 rtvFrom.DataBind()


4. As you can see, up to his point. I am using a method "GetMenuTreeSync" to retrieve the information from the database. The method actually calls a stored procedure to get the information, but it could just execute a SQL sentence like this:

select * from ME_menu WHERE Active = 1 order by me_parent

Comments:
In this example I used a Viewstate object to store the dataset returned from the query, however you can use a simple local variable of dataset or datatable type.