MySQL-带有连接语句和格式表的双和

Question

当我用总和连接两个表时，我的代码无法正常工作。

第一张桌子

create table table1 (
code int(10) primary key,
PN varchar(10) not null,
LOC varchar(10) not null,
Stock int(10) not null);

insert into table1 values (1,'T1','AAA',2);
insert into table1 values (2,'A1','AAA',2);
insert into table1 values (3,'J1','AAA',3);
insert into table1 values (4,'A2','AAA',1);
insert into table1 values (5,'J2','BBB',2);
insert into table1 values (6,'A3','BBB',3);
insert into table1 values (7,'J3','BBB',4);
insert into table1 values (8,'T1','BBB',5);
insert into table1 values (9,'A1','BBB',1);
insert into table1 values (10,'J2','CCC',3);
insert into table1 values (11,'J2','DDD',4);
insert into table1 values (12,'A1','DDD',3);
insert into table1 values (13,'J2','EEE',5);
insert into table1 values (14,'A1','AAA',15);

第二张桌子

create table table2 (
code int(10) primary key,
PN varchar(10) not null,
LOC varchar(10) not null,
Used int(10) not null,
Year int(10));

insert into table2 values (1,'T1','AAA',2, 2018);
insert into table2 values (2,'A1','AAA',2, 2018);
insert into table2 values (3,'J1','AAA',3,2017);
insert into table2 values (4,'A2','AAA',1,2018);
insert into table2 values (5,'J2','BBB',2,2017);
insert into table2 values (6,'A3','BBB',3,2017);
insert into table2 values (7,'J3','BBB',4,2016);
insert into table2 values (8,'T1','BBB',5,2016);
insert into table2 values (9,'A1','BBB',1,2018);
insert into table2 values (10,'J2','CCC',3,2018);
insert into table2 values (11,'J2','DDD',4,2018);
insert into table2 values (12,'A1','DDD',3,2018);
insert into table2 values (13,'J2','EEE',5,2017);
insert into table2 values (14,'A1','AAA',15,2018);

我想在所有位置以以下格式打印结果。我可以按以下方式获取总计，但是当我使用CASE时，它会重复值。

+------+----+-----+-------+------------+------------+
| code | PN | LOC | Stock | counttotal | TotalStock |
+------+----+-----+-------+------------+------------+
|    2 | A1 | AAA |     2 |         16 |         84 |
|    4 | A2 | AAA |     1 |          1 |          1 |
|    5 | J2 | BBB |     2 |          8 |         28 |
|    1 | T1 | AAA |     2 |          2 |          7 |
+------+----+-----+-------+------------+------------+

SELECT a.*,
Count(b.Used) as counttotal,
sum(a.Stock) TotalStock
FROM table1 a
LEFT JOIN table2 b on a.PN=b.PN WHERE b.Year > 2017
GROUP BY a.PN
ORDER BY a.PN ASC;

但是，与所有LOC的总计相反，我希望在正下方的列中包含正确的数据。

+----+----------+-----------+----------+-----------+
| PN | AAA_Used | AAA_Stock | BBB_Used | BBB_Stock |
+----+----------+-----------+----------+-----------+
| A1 |       68 |        68 |        4 |         4 |
| A2 |        1 |         1 |        0 |         0 |
| J2 |        0 |         0 |        0 |         4 |
| T1 |        4 |         2 |        0 |         5 |
+----+----------+-----------+----------+-----------+

SELECT a.PN

,SUM(CASE WHEN b.LOC = "AAA" THEN b.Used ELSE 0 END) AS "AAA_Used"
,SUM(CASE WHEN a.LOC = "AAA" THEN a.Stock ELSE 0 END) AS "AAA_Stock"
,SUM(CASE WHEN b.LOC = "BBB" THEN b.Used ELSE 0 END) AS "BBB_Used"
,SUM(CASE WHEN a.LOC = "BBB" THEN a.Stock ELSE 0 END) AS "BBB_Stock"

FROM table1 a
LEFT JOIN table2 b on a.PN=b.PN WHERE b.Year > 2017
GROUP BY a.PN, b.PN
ORDER BY a.PN ASC;