Question

我有以下查询，其中的每个部分详细说明了库存进出。我想要的是有一个表格，如下所示，每个查询详细说明进出日期。

 SELECT 
 inventory.DSTAMP,
 inventory.NAME,
 inventory.WEIGHT  AS KG_Weight,
 inventory.CODE
 FROM inventory
 WHERE inventory.code = 'In'

 UNION

 SELECT 
 inventory.DSTAMP,
 inventory.NAME,
 inventory.WEIGHT  AS KG_Weight,
 inventory.CODE
 FROM inventory
 WHERE inventory.code = 'Out'

输出为：


╔═════════╦════════════╦═════════════╗
║ Date    ║ In         ║ Out         ║
╠═════════╬════════════╬═════════════╣
║01/01/14 ║ 4500       ║ 7800        ║
║02/01/14 ║ 0          ║ 8500        ║
║03/01/14 ║ 8000       ║ 0           ║
╚═════════╩════════════╩═════════════╝

有一种简单的方法吗？

Answer 1

select DSTAMP,
       sum(case when code = 'In' then WEIGHT else 0 end) as "In",
       sum(case when code = 'Out' then WEIGHT else 0 end) as "Out"
from inventory
group by DSTAMP

Answer 2

您可以使用条件聚合：

SELECT i.DSTAMP, i.NAME,
       SUM(CASE WHENn i.CODE = 'IN' THEN i.WEIGHT END) as IN_KG_Weight,
       SUM(CASE WHENn i.CODE = 'OUT' THEN i.WEIGHT END) as OUT_KG_Weight
FROM inventory i
WHERE i.code = 'In'
GROUP BY i.DSTAMP, i.NAME;

编辑：

仅按日期对此进行分组：

SELECT to_char(i.DSTAMP, 'YYYY-MM-DD') as yyyymmdd, i.NAME,
       SUM(CASE WHENn i.CODE = 'IN' THEN i.WEIGHT END) as IN_KG_Weight,
       SUM(CASE WHENn i.CODE = 'OUT' THEN i.WEIGHT END) as OUT_KG_Weight
FROM inventory i
WHERE i.code = 'In'
GROUP BY to_char(i.DSTAMP, 'YYYY-MM-DD'), i.NAME;

这会将值转换为日期字符串，可以进行排序。

SQL连接查询

2 个答案: