这是数据库架构:
[已编辑]
我将描述我对下面的查询所做的事情:
最内层查询:选择所有满足WHERE
条件的saleId
中间查询:选择属于 saleId
一部分的所有 productId
最外层查询:SUM
products.cost
并选择vendors.name
。
这是我想出的 SQL 查询:
SELECT vendors.name AS Company
, SUM(products.cost) AS Revenue
FROM
products
INNER JOIN sold_products
ON (products.productId = sold_products.productId)
INNER JOIN vendors
ON (products.vendorId = vendors.vendorId)
WHERE sold_products.productId IN (
SELECT sold_products.productId
FROM
sold_products
WHERE sold_products.saleId IN (
SELECT sales.saleId
FROM
markets
INNER JOIN vendors
ON (markets.vendorId = vendors.vendorId)
INNER JOIN sales_campaign
ON (sales_campaign.marketId = markets.marketId)
INNER JOIN packet_headers
ON (sales_campaign.packetHeaderId = packet_headers.packetHeaderId)
INNER JOIN packet_details
ON (packet_details.packetHeaderId = packet_headers.packetHeaderId)
INNER JOIN sales
ON (sales.packetDetailsId = packet_details.packetDetailsId)
WHERE vendors.customerId=60
)
)
GROUP BY Company
ORDER BY Revenue DESC;
对优化有什么帮助吗?
最佳答案
由于您只是使用内部联接,因此通常将查询简化为如下所示:
SELECT ve.name AS Company
, SUM(pr.cost) AS Revenue
FROM products pr
, sold_products sp
, vendors ve
, markets ma
, sales_campaign sc
, packet_headers ph
, packet_details pd
, sales sa
Where pr.productId = sp.productId
And pr.vendorId = ve.vendorId
And ve.vendorId = ma.vendorId
And sc.marketId = ma.marketId
And sc.packetHeaderId = ph.packetHeaderId
And pd.packetHeaderId = ph.packetHeaderId)
And sa.packetDetailsId = pd.packetDetailsId
And ve.customerId = 60
GROUP BY ve.Company
ORDER BY pr.Revenue DESC;
请尝试一下这是否有效,如果速度更快,请告诉我。
关于mysql - 如何优化这个嵌套的 SQL 查询,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/13331355/