以下查询按预期方式工作。
但是从中选择数据的汇总表太大。查询需要很多时间。
SELECT s.date_time AS date_time,SUM(s.requests) AS sum_requests,SUM(s.impressions) AS sum_views,SUM(s.clicks) AS sum_clicks,SUM(s.conversions) AS sum_conversions,
SUM(s.total_revenue) AS sum_revenue,SUM(s.total_revenue) AS sum_spend,
SUM(s.total_basket_value) AS sum_bv,SUM(s.total_num_items) AS sum_num_items,SUM(s.total_pubrevenue) AS sum_pubrevenue
FROM ox_data_summary_ad_hourly AS s
INNER JOIN ox_banners AS d ON (d.bannerid=s.ad_id)
INNER JOIN ox_campaigns AS m ON (m.campaignid=d.campaignid)
INNER JOIN ox_clients AS a ON (a.clientid=m.clientid)
LEFT JOIN ox_zones AS z ON (z.zoneid=s.zone_id)
LEFT JOIN ox_affiliates AS p ON (p.affiliateid=z.affiliateid)
WHERE a.agencyid = 3 AND z.zone_type = 'application' AND z.delivery = 8
AND s.date_time>='2012-07-01 00:00:00' AND s.date_time<='2012-07-01 23:59:59'
GROUP BY date_time
我需要简化联接。有什么方法可以为所有联接创建一个临时表，然后将该表联接到基表。
到目前为止，这是我尝试过的。
drop table if exists test.helper;
create table test.helper
select d.network_type , d.is_network, d.bannerid, p.agencyid, z.zone_type, z.delivery , z.zoneid
FROM ox_banners as d
INNER JOIN ox_campaigns AS m ON (m.campaignid=d.campaignid)
INNER JOIN ox_clients AS a ON (a.clientid=m.clientid)
left JOIN ox_agency as oa ON (oa.account_id = a.clientid)
left JOIN ox_affiliates AS p ON (p.agencyid = oa.agencyid)
left JOIN ox_zones AS z ON (z.affiliateid = p.affiliateid);
alter table test.helper add key(bannerid, zoneid);
但是，当与原始表连接时，它不会返回正确的结果。
SELECT s.ad_id, s.date_time AS date_time,SUM(s.requests) AS sum_requests,SUM(s.impressions) AS sum_views,SUM(s.clicks) AS sum_clicks,SUM(s.conversions) AS sum_conversions,
SUM(s.total_revenue) AS sum_revenue,SUM(s.total_revenue) AS sum_spend,
SUM(s.total_basket_value) AS sum_bv,SUM(s.total_num_items) AS sum_num_items,SUM(s.total_pubrevenue) AS sum_pubrevenue
FROM ox_data_summary_ad_hourly AS s
inner JOIN test.helper AS d ON (d.bannerid=s.ad_id )
where d.agencyid = 3 AND d.zone_type = 'application' AND d.delivery = 8 and s.date_time>='2012-07-01 00:00:00' AND s.date_time<='2012-07-01 23:59:59'
GROUP BY date_time
最佳答案
首先，我将LEFT JOIN替换为INNER JOINS。由于在ox_zones上具有WHERE子句，因此LEFT JOIN创建的空值仍然会丢失。外部连接显然很昂贵，应尽可能避免。
在合理的现代RDBMS上，通过创建临时表对查询计划程序进行二次猜测通常会适得其反。是否已索引所有加入条件？ WHERE子句中引用的列是否已编制索引？
关于mysql - 临时表而不是联接，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/12559011/