[英]MySQL with stock maintain
我有一个简单的程序来管理某些车辆的燃料发放状态
即包括下表
+---------+-----------+--------+
| item_id | item_name | status |
+---------+-----------+--------+
| 1 | Diesel | 1 |
+---------+-----------+--------+
+------------+------------+
| vehicle_id | vehicle_no |
+------------+------------+
| 1 | 4545 |
| 2 | 4546 |
| 3 | 4547 |
| 18 | 4548 |
+------------+------------+
+-----------------+------------+---------+--------+
| update_stock_id | bill_date | bill_no | status |
+-----------------+------------+---------+--------+
| 1 | 2019-09-25 | 123 | 1 |
| 2 | 2019-09-26 | 456 | 1 |
+-----------------+------------+---------+--------+
+-------------------------+-----------------+------+-----+--------+
| update_stock_details_id | update_stock_id | item | qty | status |
+-------------------------+-----------------+------+-----+--------+
| 1 | 1 | 1 | 900 | 1 |
| 2 | 2 | 1 | 800 | 1 |
+-------------------------+-----------------+------+-----+--------+
+---------+------------+-------------+------+----------+
| fuel_id | vehicle_id | issued_date | item | fuel_qty |
+---------+------------+-------------+------+----------+
| 1 | 2 | 2019-09-25 | 1 | 50 |
| 2 | 2 | 2019-09-25 | 1 | 50 |
| 3 | 18 | 2019-09-26 | 1 | 25 |
| 4 | 2 | 2019-09-27 | 1 | 50 |
+---------+------------+-------------+------+----------+
select sum(store_update_stock_details.qty) - tbl_fuel.fuel_qty as qty
from store_update_stock_details
inner join store_update_stock on store_update_stock_details.update_stock_id=store_update_stock.update_stock_id
join store_item on store_update_stock_details.item=store_item.item_id
join tbl_fuel on store_item.item_id=tbl_fuel.item
where store_update_stock.status=1
group by store_item.item_id
+------+
| qty |
+------+
| 1525 |
+------+
但是代码生成如下output
+------+
| qty |
+------+
| 6750 |
+------+
我不明白可能出了什么问题。 谁能帮我?
您的查询的主要问题是,因为您在tbl_fuel
中有多行与库存更新详细信息表中的相同item
匹配,所以您最终在结果集中有多行被求和(因此大于预期的结果) . 要解决此问题,您需要分别在每个表中逐项进行总和,然后减去结果:
select susd.qty - tf.fuel_qty as qty
from (select susd.item, sum(susd.qty) AS qty
from store_update_stock_details susd
join store_update_stock sus on sus.update_stock_id = susd.update_stock_id
where sus.status = 1
group by item) susd
join store_item si on susd.item = si.item_id
join (select item, sum(fuel_qty) AS fuel_qty
from tbl_fuel
group by item) tf on si.item_id=tf.item
Output:
qty
1525
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