在MYSQL中，查询存储在5个仓库中每个产品的SUM数量> 100的产品名称

Question

请帮我使用mysql进行查询，显示所有5个仓库中总数量SUM(goods.quantity) > 100的产品(product.name)，指定数量最多的仓库(warehouse.name)每个产品的。以下是所有表格的示意图，以便更好地理解：

image of warehouses database

我正在尝试这个查询：

SELECT product.name AS product, warehouse.name AS warehouse 
FROM product, warehouse, goods 
WHERE goods.productId = product.id AND goods.warehouseId = warehouse.id 
GROUP BY product.name, warehouse.name 
HAVING SUM(goods.quantity)>100;

它给了我以下信息：

product	warehouse
engine	New York
right back door	New York
main frame	London
left back door	London
back lights	London
steering wheel	Sydney
wheel	Toronto
car cleaner	Toronto

但它只显示所有仓库中具有goods.quantity > 100 的产品，而不是SUM(goods.quantity) > 100。

此外，它不显示每种产品数量最多的仓库，而是显示有该产品的任何仓库。

Answer 1

尝试在所选字段中添加SUM(goods.quantity) 以显示该号码 你也可以ORDER BY SUM(goods.quantity) DESC，所以最高数量在顶部。

SELECT product.name AS product, warehouse.name AS warehouse, SUM(goods.quantity) FROM product, warehouse, goods WHERE goods.productId = product.id AND goods.warehouseId = warehouse.id GROUP BY product.name, warehouse.name HAVING SUM(goods.quantity)>100;

Answer 2

您可以尝试使用您的查询作为子查询结果来计算仓库的数量

    select products 
    from  (
        SELECT product.name AS product, warehouse.name AS warehouse 
        FROM product
        INNER JOIN warehouse  goods.warehouseId = warehouse.id 
        INNER JOIN  goods goods.productId = product.id AND
        WHERE goods.productId = product.id AND goods.warehouseId = warehouse.id 
        GROUP BY product.name, warehouse.name 
        HAVING SUM(goods.quantity)>100;

    ) t 
    group by products
    having count(distinct warehouse) = 5

Answer 3

您必须逐步完成此操作。首先，您需要每个产品的总数量和最大数量。这样你就可以决定是否展示这个产品，然后展示什么仓库。这意味着首先是聚合，然后是一些连接。

最后你必须准备好有关系（每个产品的最大数量相同的两个仓库）。您可以使用GROUP_CONCAT 获取*仓库列表。

select 
  p.id,
  p.name as product_name,
  group_concat(w.name) as warehouse_names
from
(
  select 
    productid, 
    max(quantity) as max_qantity
  from goods
  group by productid
  having sum(quantity) > 100
) base
join product p on p.id = base.productid
join goods g on g.productid = base.productid and p.quantity = base.max_qantity
join warehouse w on w.id = g.warehouseid
group by p.id
order by product_name;