Question

我有两张表如下。

产品

+-----------------------------+
| id      min_stock  is_order |
+-----------------------------+
| p1      5           y       |
| p2      6           y       |
| p3      5           y       |
| p4      0           n       |
+-----------------------------+

库存

+-----------------------------+
| id    product_id   quantity |
+-----------------------------+
| 1       p1          3       |
| 2       p1          5       |
| 3       p2          2       |
+-----------------------------+

现在我想要is_order状态为y且其sum(quantity)<= min_stock的所有记录。

对不起，可能是我的判决不会清楚你。但是在我的结果之后，应该得到product_id。

P2
p3

我该怎么做？

Answer 1

您可以使用APPLY获取sum_quantity：

SQL Fiddle

SELECT p.product_id
FROM product p
OUTER APPLY(
    SELECT SUM(quantity) AS sum_quantity
    FROM Stock
    WHERE product_id = p.product_id
)s
WHERE
    p.is_order= 'y'
    AND (
        s.sum_quantity IS NULL 
        OR s.sum_quantity <= p.min_stock
    )

或者，您可以使用LEFT JOIN和SUM以及HAVING：

SQL Fiddle

SELECT p.product_id
FROM product p
LEFT JOIN Stock s
    ON s.product_id = p.product_id
WHERE
    p.is_order = 'y'
GROUP BY p.product_id, p.min_stock
HAVING SUM(ISNULL(s.quantity, 0)) <= p.min_stock

Answer 2

select p.* 
from product p 
inner join (
    select 
        product_id, SUM(quantity)quantity
    from stock 
    group by product_id
) s on p.id = s.product_id 
where 
    s.quantity <= p.min_stock 
    and p.is_order = 'y'

Answer 3

;with cte(product_id , quantity )
AS
(
  select product_id, sum(quantity)
  from Stock
  group by product_id 
)

select * from
Product p
left join cte s on p.product_id = s.product_id
where p.order_status = 'y'  and min_stock <> 0
and isnull(s.quantity,-1) < p.min_stock

http://www.sqlfiddle.com/#!3/78470/14

Answer 4

CREATE TABLE #product
    (id varchar(2), min_stock int, is_order varchar(1))
;

INSERT INTO #product
    (id, min_stock, is_order)
VALUES
    ('p1', 5, 'y'),
    ('p2', 6, 'y'),
    ('p3', 5, 'y'),
    ('p4', 0, 'n')
;


CREATE TABLE #Stock
    (id int, product_id varchar(2), quantity int)
;

INSERT INTO #Stock
    (id, product_id, quantity)
VALUES
    (1, 'p1', 3),
    (2, 'p1', 3),
    (3, 'p2', 2)
;


select b.id from 
(select product_id,sum(quantity) sum from #Stock group by product_id) a
right join   #product  b on a.product_id=b.id
where isnull(a.sum,0)<=b.min_stock and b.is_order='y'

1个表列与另一个表列的总和的比较

4 个答案: