加入4个表需要帮助

Question

我有4张桌子。

T1

    +------+-------+-------------+------+
    | type | pcode | ccode       | amnt |
    +------+-------+-------------+------+
    | s    |     1 |        1801 | 1000 |
    | s    |     1 |        1801 | 2000 |
    | s    |     1 |        1801 | 3000 |
    | s    |     2 |        1802 | 1500 |
    | s    |     3 |        1802 | 2500 |
    +------+-------+-------------+------+

T2

+-------+-------+
| btype | Ccode |
+-------+-------+
|     0 |  1701 | 
|     0 |  1801 |
|     0 |  1801 |  
|     1 |  1801 |
|     0 |  1802 | 
|     1 |  1802 |  
+-------+-------+

T3

+-------+------+-------+
| pcode | name | scode |  
+-------+------+-------+
|     1 | pep  |  1001 |  
|     2 | coke |  1002 |  
+-------+------+-------+

T4

+------+------+
| code | name |
+------+------+
| 1001 | pep  |
| 1002 | coke |
+------+------+

我需要的结果集应满足以下条件。

如果bill type = 0，我需要t4.code，t4.name，sum（amount）为s1，如果billtype = 1，我需要sum（t1.amount）为s2

，结果集应为

+------+------+------+------+
| Code | name |  s1  |  s2  |
+------+------+------+------+
| 1001 | pep  | 3000 | 3000 |
| 1002 | coke | 1500 | 2500 |
+------+------+------+------+

Answer 1

You could use inner join and case for filter then values to sum

select t4.code, t4.name
  , sum(CASE WHEN t2.btype=0 then T1.amnt else 0 end) s1
  , sum(CASE WHEN t2.btype=1 then T1.amnt else 0 end) s2

from T4
INNER JOIN T3 on T3.scode = T4.code
INNER JOIN T1 on T3.pcode = T1.pcode
INNER JOIN T2 on T1.ccode = t2.ccode