下拉使用LINQ

Question

我使用這樣

string query = "Select Id,Name+':'+Distribution_name+' 'as Name1 from BR_supervisor where((id not in (select SupId from tbluser where active='true')) and active='true') "; 

    DropDownList3.DataTextField = "Name1"; 
    DropDownList3.DataValueField = "Id"; 
    DropDownList3.DataBind(); 

SQL現在，我想我的查詢轉換爲LINQ表達式和綁定下拉結合兩列到一個下拉兩列的結合。這個怎麼做？

Answer 1

var query = from s in db.BR_supervisor 
      join u in db.tbluser.Where(x => x.active) 
       on s.id equals u.SupId into g 
      where s.active && !g.Any() 
      select new { 
       s.Id, 
       Name1 = s.Name + ":" + s.Distribution_name 
      }; 

DropDownList3.DataTextField = "Name1"; 
DropDownList3.DataValueField = "Id"; 
DropDownList3.DataSource = query; 
DropDownList3.DataBind(); 

這產生SQL等：

SELECT [t0].[Id], ([t0].[Name] + @p0) + [t0].[Distribution_name] AS [Name1] 
FROM [BR_supervisor] AS [t0] 
WHERE ([t0].[active] = 1) AND (NOT (EXISTS(
    SELECT NULL AS [EMPTY] 
    FROM [tbluser] AS [t1] 
    WHERE ([t0].[id] = [t1].[SupId]) AND ([t1].[active] = 1) 
    ))) 

Answer 2

var query2 = (from a in this._projectDataContx.BR_Supervisors 
         where ((!(from x in this._projectDataContx.tblUsers 
           where (x.Active == true) 
           select x.SupId).Contains(a.Id))&&(a.Active==true)) 
         select new { Name1 = a.Name + ":" + a.Distribution_Name, a.Id }); 
     DropDownList3.DataSource = query2; 
     DropDownList3.DataTextField = "Name1"; 
     DropDownList3.DataValueField = "Id"; 
     DropDownList3.DataBind();