Mysql Query使用多个连接，分组和sum（）获取最新记录

Question

SELECT Task_Entry_Icode, Task_Master_Icode, Work_Progress,SUM(A.Logged_Hours) as logged,B.*

FROM task_entry一个INNER JOIN task_master B on A.Task_Master_Icode = B.Task_Icode

WHERE Task_Entry_Icode IN（

SELECT MAX(Task_Entry_Icode)

FROM task_entry

GROUP BY Task_Master_Icode

）;

Answer 1

SELECT * FROM task_master INNER JOIN task_entry B ON A.Task_Icode = B.Task_Master_Icode 在哪里Created_On IN（     SELECT MAX（Cre​​ated_On）     FROM task_entry     GROUP BY Task_Master_Icode ）和A. A.Task_Created_By =＆＃39; 7＆＃39;;

  

这适合我，但如果我使用sum（）它只返回一个记录

Answer 2

SELECT 
  B.Task_Entry_Icode, 
  B.Task_Master_Icode, 
  (SELECT Work_Progress FROM task_entry WHERE Task_Master_Icode=B.Task_Master_Icode ORDER BY B.Created_On DESC LIMIT 1 OFFSET 0),
  SUM(B.Logged_Hours)
FROM 
  task_master A INNER JOIN task_entry B ON A.Task_Icode=B.Task_Master_Icode
GROUP BY 
  B.task_master_icode;