我正在尝试添加四个表，如果数据存在，我想添加三个表中的值然后它想添加值否则它想将 0 添加到该值我使用左连接使用它我得到不同的值
MariaDB [kjpuram]> select centercode, aarrears,medicine, aothers from school_additions;
+------------+----------+----------+---------+
| centercode | aarrears | medicine | aothers |
+------------+----------+----------+---------+
| 107 | 0 | 0 | 13250 |
| 102 | 0 | 0 | 100000 |
| 107 | 100000 | 0 | 0 |
| 107 | 12540 | 0 | 0 |
+------------+----------+----------+---------+
4 rows in set (0.027 sec)
MariaDB [kjpuram]> select sum(net),centercode from school_daily_data group by centercode;
+--------------------+------------+
| sum(net) | centercode |
+--------------------+------------+
| 556391.968 | 102 |
| 13877.835 | 103 |
| 210642.76699999993 | 107 |
+--------------------+------------
对于 107 中心代码，我想要 323892.767
MariaDB [kjpuram]> select C.id id,D.centercode centercode,round(sum(D.net),3) amount,COALESCE(L.installment_amt,0) lamount,round(COALESCE((sum(D.net)+COALESCE(sum(A.cartage),0)+COALESCE(sum(A.autofine),0)+COALESCE(sum(A.aarrears),0)+COALESCE(sum(A.aothers),0)+COALESCE(sum(A.commission),0)-COALESCE(sum(A.cattlefeed),0)-COALESCE(sum(A.stores),0)-COALESCE(sum(A.medicine),0)-COALESCE(sum(A.stationary),0)-COALESCE(sum(A.emtcharges),0)-COALESCE(sum(A.seed),0)-COALESCE(sum(A.insurance),0)-COALESCE(sum(A.rarrears),0)-COALESCE(sum(A.rothers),0)-COALESCE(sum(L.installment_amt),0)),0),3) net from school_center C join school_daily_data D on C.centre_code = D.centercode and D.date between '2021-03-01' and '2021-03-31' left join school_additions A on C.centre_code = A.centercode and A.date between '2021-03-01' and '2021-03-31' left join school_loanbillsdata L on C.centre_code = L.centercode and L.idate between '2021-03-01' and '2021-03-31' group by D.centercode,A.centercode;
+----+------------+------------+---------+-------------+
| id | centercode | amount | lamount | net |
+----+------------+------------+---------+-------------+
| 37 | 102 | 556391.968 | 0 | 6756391.968 |
| 38 | 103 | 13877.835 | 0 | 13877.835 |
| 40 | 107 | 631928.301 | 0 | 4531418.301 |
+----+------------+------------+---------+-------------+
3 rows in set (0.007 sec)
当我使用这个查询时，我得到了这个值