如何使用MySql和PHP存储/处理多个表的数据

Question

I have 5 different MySql tables viz:

u_t (uid, pwd, field1, field2)

t_1 (tid_1, ut_uid, field_1, field_2, points)

t_2 (tid_2, ut_uid, field_1, field_2, points)

t_3 (tid_3, ut_uid, field_1, field_2, points)

t_4 (tid_4, ut_uid, field_1, field_2, points)

PS: uid=pk , tid_1,2,3,4=pk, ut_uid=fk

All the above tables are having some information based on some unique features.

Now i want to get the sum of points from each table for every user for storing and displaying purpose, using PHP.

Answer 1

try

select u_t.uid, 
       sum(t_1.points+t_2.points+t_3.points+t_4.points+t_5.points) as total_p
from u_t
left outer join t_1 on t_1.ut_uid = u_t.uid
left outer join t_2 on t_2.ut_uid = u_t.uid
left outer join t_3 on t_3.ut_uid = u_t.uid
left outer join t_4 on t_4.ut_uid = u_t.uid
group by u_t.uid

Answer 2

An uglier version of this:

SELECT ut.uid, sum(t1.pts + t2.pts + t3.pts + t4.pts) total
FROM u_t ut
LEFT JOIN
(
  SELECT ut_uid, sum(points) pts
  FROM t_1
  GROUP BY ut_uid
) t1
  on ut.uid = t1.ut_uid
LEFT JOIN
(
  SELECT ut_uid, sum(points) pts
  FROM t_2
  GROUP BY ut_uid
) t2
  on ut.uid = t2.ut_uid
LEFT JOIN
(
  SELECT ut_uid, sum(points) pts
  FROM t_3
  GROUP BY ut_uid
) t3
  on ut.uid = t3.ut_uid
LEFT JOIN
(
  SELECT ut_uid, sum(points) pts
  FROM t_4
  GROUP BY ut_uid
) t4
  on ut.uid = t4.ut_uid
GROUP BY ut.uid