MySQL查询的影响

我想弄清楚为什么我的MySQL查询需要一分钟才能运行。我无法弄清楚我是否低效地编程某些东西，或者我是否应该预期像这样的滞后时间。以下是代码。MySQL查询的影响

请记住，在我搜索的大部分表格（货件，shipment_financials，shipment_consignees，shipment_shippers）中，有10,000到30,000条记录。

下面是代码：

 
SELECT users.*, COUNT(DISTINCT shipments.shipment_id) as COUNT_SHIPMENTS, COUNT(DISTINCT clients.client_id) as COUNT_CLIENTS, SUM(shipment_financials.shipment_financial_revenue) as SUM_USER_REVENUE, SUM(shipment_financials.shipment_financial_cost) as SUM_USER_COST 
FROM users 
JOIN shipments ON shipments.shipment_details_sales_rep = users.user_id 
LEFT JOIN shipment_financials ON shipment_financials.shipment_financial_shipment_id = shipments.shipment_id 
JOIN clients ON clients.client_id = shipments.shipment_details_client 
JOIN shipment_consignees ON shipment_consignees.shipment_consignee_shipment_id = shipments.shipment_id 
JOIN shipment_shippers ON shipment_shippers.shipment_shipper_shipment_id = shipments.shipment_id 

WHERE shipment_consignees.shipment_consignee_id = (
     SELECT MAX(shipment_consignees.shipment_consignee_id) 
     FROM shipment_consignees 
     WHERE shipments.shipment_id = shipment_consignees.shipment_consignee_shipment_id 
    ) 
    AND shipment_shippers.shipment_shipper_id = (
     SELECT MIN(shipment_shippers.shipment_shipper_id) 
     FROM shipment_shippers 
     WHERE shipments.shipment_id = shipment_shippers.shipment_shipper_shipment_id 
    ) 
    AND users.user_account_id = $account_id 
    AND shipments.shipment_voided = 0 
GROUP BY users.user_id 
ORDER BY SUM_USER_REVENUE desc

来源

2016-06-14 Brad H

因为不是快速奔跑：大量的记录，5连接，多个相关子查询。 –

'解释'它，并做一些优化。 – Blank

你使用索引吗？它会大大提高性能 – andrew

主要表现在对嵌入式查询where语句也减慢了查询的处理。但是，如果它不可避免并且必须使用内联查询，则可以通过执行“LEFT OUTER JOIN”来减少“JOIN”的输出。

“users。*”也从表格中提取整个记录，从而减慢了记录速度，但仍然认为加入是减慢查询速度的主要问题。

来源

2016-06-14 05:35:13

这是连接和多个查询。诀窍是将我需要的信息保存在一张表中（发货表）。这样我不必加入多个表格。

不是最有趣的方式来完成它，但人做它加快了速度！

来源

2016-06-16 06:20:22

这听起来不像是一个解决方案:-( – Strawberry

你可能可以解释你的查询使用以下命令

*explain SELECT 
     users.* 
     ,COUNT(DISTINCT shipments.shipment_id) as COUNT_SHIPMENTS 
     ,COUNT(DISTINCT clients.client_id) as COUNT_CLIENTS 
     ,SUM(shipment_financials.shipment_financial_revenue) as SUM_USER_REVENUE 
     ,SUM(shipment_financials.shipment_financial_cost) as SUM_USER_COST 
FROM users 
JOIN shipments 
    ON shipments.shipment_details_sales_rep = users.user_id 
LEFT JOIN shipment_financials 
    ON shipment_financials.shipment_financial_shipment_id = shipments.shipment_id 
JOIN clients 
    ON clients.client_id = shipments.shipment_details_client 
JOIN shipment_consignees 
    ON shipment_consignees.shipment_consignee_shipment_id = shipments.shipment_id 
JOIN shipment_shippers 
    ON shipment_shippers.shipment_shipper_shipment_id = shipments.shipment_id 
WHERE shipment_consignees.shipment_consignee_id = 
    (
     SELECT MAX(shipment_consignees.shipment_consignee_id) 
     FROM shipment_consignees 
     WHERE shipments.shipment_id = shipment_consignees.shipment_consignee_shipment_id 
    ) 
AND shipment_shippers.shipment_shipper_id = 
    (
     SELECT MIN(shipment_shippers.shipment_shipper_id) 
     FROM shipment_shippers 
     WHERE shipments.shipment_id = shipment_shippers.shipment_shipper_shipment_id 
    ) 
AND users.user_account_id = [TEST ACCOUNT ID] 
AND shipments.shipment_voided = 0 
GROUP BY users.user_id 
ORDER BY SUM_USER_REVENUE desc;*

，将帮助您优化查询

来源

2016-06-16 07:33:36

MySQL查询的影响

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