如何在Linq中進行兩次連接

Question

我試圖將sql查詢寫入linq：

查詢：

select s.s_name, sub.state, sub.to, sub.evaluation, sub.task_id
from submit_task sub
join student s on s.id=sub.student_id
join task t on t.id=sub.task_id
where t.t_name = "bbbb";

Linq：

var subTask = (from sub in ado.submit_task
               join s in ado.student on sub.student_id equals s.id
               join t in ado.task on sub.task_id equals t.id
               where t.t_name == listView3.SelectedItems[0].Text
               select new { s.s_name, sub.state, sub.to, 
                            sub.evaluation, sub.task_id });

但這不起作用。 當我嘗試使用dubugg時，沒有任何反應，沒有錯誤或結果。 你看到錯誤了嗎？

謝謝你

Answer 1

var text = listView3.SelectedItems[0].Text;

var subTask = (from sub in ado.submit_task
  join s in ado.student on sub.student_id equals s.id
  join t in ado.task on sub.task_id equals t.id
  where t.t_name == text
  select new { s.s_name, sub.state, sub.to, sub.evaluation, sub.task_id });