我有一个查询,可以获取过去一年内登录过的所有用户ID。
查询1:
SELECT user_id, user_name
FROM logins
WHERE login_date BETWEEN "2015-09-01" AND "2016-09-01"
GROUP BY user_id;
Execution time: 625ms
另一个类似于上面的查询,现在有了额外的过滤器来列出带有'jeff'的用户名。
QUERY2:
SELECT user_id, user_name
FROM logins
WHERE login_date BETWEEN "2015-09-01" AND "2016-09-01"
AND user_name LIKE '%jeff%'
GROUP BY user_id;
Execution time: 587ms
总执行时间为1212毫秒。
我只使用Query1来获取一年内登录用户的总数,而使用Query2来获取user_name的用户列表,如'jeff'。
问题是,我需要执行两个查询并且需要更长时间。
有没有办法将两个查询合并为一个并获取我需要的数据,即登录用户的总数和user_name的登录用户列表,如'jeff'?同时最小化执行时间?
示例数据:
user_id user_name login_date
1 annie 2015-10-02
2 greg 2015-12-25
3 jeff 2015-11-05
4 aljeffar 2016-03-06
5 jeff1 2015-07-07
2 greg 2016-01-30
1 annie 2015-11-13
3 jeff 2016-02-14
2 greg 2016-09-30
3 jeff 2016-07-04
查询1结果:
user_id user_name 1 annie 2 greg 3 jeff 4 aljeffar Total result count: 4 -- this should be the fix value of total_loggedin_users column below
Query2结果:
user_id user_name 3 jeff 4 aljeffar
预期的最终结果:
user_id user_name total_loggedin_users 3 jeff 4 4 aljeffar 4
答案 0 :(得分:1)
a[1:2]
只运行一次并添加一个条件总和来计算jeffs。
答案 1 :(得分:1)
如果您希望结果只显示像jeff这样的user_name,并且还有整体计数,那么您可以尝试:
需要执行Subselect以获取列中的总计数。更新的查询:
SELECT [USER_ID] ,
[USER_NAME] ,
CountAll
FROM ( SELECT [USER_ID] ,
[USER_NAME] ,
-- Window-Function (Only in SQL-Server) to get overall count
COUNT([USER_ID]) OVER ( ) AS CountAll
FROM dbo.logins
WHERE login_date BETWEEN '2015-09-01' AND '2016-09-01'
--Group so we don't count multiple logins of one user
GROUP BY [USER_ID] ,
[USER_NAME]
) subselect
WHERE [USER_NAME] LIKE '%jeff%'
答案 2 :(得分:0)
试试这个。其他变种。
SELECT user_id, user_name, GROUP_CONCAT(user_name) AS list_of_jeffs, COUNT(*) AS total, SUM(IF(user_name LIKE "%jeff%",1,0)) as jeff
FROM `pt_terminal`
WHERE login_date BETWEEN "2015-09-01" AND "2016-09-01"
GROUP BY user_id;