實體查詢選擇TOP1

Question

具有SQL的問題，我用ExecuteStoreQuery請參閱以低於

的例子我的編碼

private void ChildMenuItem() 
    { 
     using (LEWREDBEntities ctx = new LEWREDBEntities()) 
     { 
      string result = @" 

       WITH ctLevel 
       AS 
       (
        SELECT 
         C_TASK_ID                AS Child 
         ,P_Task_ID                AS Parent 
         ,common_task. TASK_SEQ            AS taskSeq 
         ,1                  AS [Level] 
         ,CAST(TASK_SEQ AS VARCHAR(MAX))          AS [taskOrder] 
         ,CAST (Replicate('', 1) + common_task.TASK_NAME AS VARCHAR(MAX))  AS [Task_Name] 
        FROM 
         [COMMON.TASK_REL] as common_task_rel, 
         [COMMON.TASK] as common_task 
        WHERE 
         common_task_rel.C_TASK_ID = common_task.TASK_ID 
         and  common_task.[TASK_TYPE] = 'F' AND common_task.[MODULE_CODE] = 'PRODE' AND common_task.[STATUS] <> 'D' 
         and C_TASK_ID =357 

        UNION ALL 

        SELECT 
         C_TASK_ID                 AS Child 
         ,P_Task_ID                 AS Parent 
         ,common_task. TASK_SEQ             AS taskSeq 
         ,[Level] + 1                AS [Level] 
         ,[taskOrder] + '.' + CAST(TASK_SEQ AS VARCHAR(MAX))       AS [taskOrder] 
         ,CAST (Replicate('', [Level] + 1) + common_task.TASK_NAME AS VARCHAR(MAX)) AS [Task_Name] 
        FROM 
         [COMMON.TASK_REL]as common_task_rel 
        INNER JOIN 
         ctLevel 
        ON 
         (P_Task_ID = Child) , 
         [COMMON.TASK] as common_task 

        WHERE 
          common_task_rel.C_TASK_ID = common_task.TASK_ID 
        and  common_task.[TASK_TYPE] = 'F' AND common_task.[MODULE_CODE] = 'PRODE' AND common_task.[STATUS] <> 'D' 
        ) 

        SELECT 
        common_task.Task_Name, 
        common_task_url.TASK_URL, 
        ctLevel.CHILD 

        FROM 
        ctLevel, 
        [COMMON.ACL] as common_acl, 
        [COMMON.STAFF_ROLE] as common_staff_role, 
        [COMMON.TASK_URL] as common_task_url, 
        [COMMON.TASK] as common_task, 
        [COMMON.STAFF_MODULE] as common_staff_module, 
        [common.module] as common_module 

        where ctLevel.Level =3 
        and ctLevel.Child = common_acl.TASK_ID 
        and common_acl.READ_ACCESS ='Y' 
        and common_acl.STATUS <>'D' 
        and common_acl.ROLE_ID = common_staff_role.ROLE_ID 
        and common_staff_role.STATUS <>'D' 
        and common_staff_role.STAFF_ID ='user' 
        and common_staff_role.STAFF_ID = common_staff_module.STAFF_ID 
        and common_staff_module.MODULE_CODE =common_module.MODULE_CODE 
        and common_staff_module.STATUS<>'D' 
        and common_staff_module.MODULE_CODE = common_module.MODULE_CODE 
        and common_module.STATUS <>'D' and common_module.MODULE_CODE ='PRODE' 
        and common_acl.TASK_ID = common_task.TASK_ID 
        and common_task.STATUS <>'D' 
        and common_task.TASK_TYPE ='F' 
        and common_task.TASK_POSITION ='S' 
        and common_task.TASK_ID = common_task_url.TASK_ID 
        and common_task_url.DEFAULT_URL ='Y' 
        and common_task_url.STATUS<>'D' 


        Group By  
          [taskOrder],common_task.Task_Name, TASK_URL,ctLevel.CHILD 

        order by [taskOrder],common_task.Task_Name, TASK_URL,ctLevel.CHILD"; 

      var query = ctx.ExecuteStoreQuery<dlcGvTask> 
       (result); 


      foreach (dlcGvTask gvTask in query.ToList()) 
      { 
       MenuItem navigation = new MenuItem(gvTask.TASK_NAME, gvTask.Child.ToString(), "",""); 
       MenuChild.Items.Add(navigation); 
      } 

      //Here???? 
      var id = (from table in query 
         select table.Child).Take(1); 

      ; 

     } 

    } 

現在，我得到一個question.How我可以選擇的頂部1記錄？

Answer 1

在你的代碼

//Here???? 
    var id = (from table in query 
       select table.Child).Take(1); 

嘗試

var id = query.First(); 
//Or 
var id = query.Take(1); 

Answer 2

嘗試做這樣的事情： -

Select Top 1 ..... ; 

OR

..... Where ROW_NUMBER() = 1;