Mysql 使用同一表上的左联接的成员资格续订报告

我有两张桌子：

Member
'id'
'name'

Membership
'id'
'site_id'
'member_id'
'year'

我想建立一个报告，以便在这样的年份跟踪订阅情况：

站点id

2019年认购总额

2018年认购总额

新建（首次订阅该网站）

续约（2019年和2018年在同一地点续约）

丢失（2018年完成但未在2019年完成该现场的潜水艇）

我在同一张

会员资格

表中的两个左连接上苦苦挣扎，如下所示：

SELECT m.site_id, 
count(m2019.id) as total2019, 
count(m2018.id) as total2018, 
SUM(IF(m2019.member_id IS NOT NULL AND m2018.member_id IS NULL, 1, 0)) new, 
SUM(IF(m2019.member_id IS NOT NULL AND m2018.member_id IS NOT NULL AND m2018.site_id = m2019.site_id, 1, 0)) renewal, 
SUM(IF(m2018.member_id IS NOT NULL AND m2019.member_id IS NULL, 1, 0)) lost 
FROM membership m 
LEFT JOIN membership m2019 ON m.id = m2019.member_id AND m.year = '2019' AND m2019.year = '2019' AND m.site_id = m2019.site_id 
LEFT JOIN membership m2018 ON m.id= m2018.member_id AND m.year = '2018' AND m2018.year = '2018' AND m.site_id = m2018.site_id 
GROUP BY m.site_id;

计数是正确的，但条件是不正确的，所以我很确定我的查询是不正确的。 我在上面已经很久了，我开始觉得有点失落

谁能帮我找出哪里做错了？

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谢谢

我认为您可以通过两个级别的聚合来做您想做的事情：

SELECT m.site_id, 
       SUM( m.max_year = 2019 ) as total2019, 
       SUM( m.min_year = 2018 ) as total2018,
       SUM( m.min_year = 2019 AND m.max_year = 2019 ) as new2019,
       SUM( m.min_year = 2018 and m.max_year = 2018 ) as renewals,
       SUM( m.max_year = 2018 ) as lost
FROM (SELECT m.id, m.site_id, MIN(year) as min_year, MAX(year) as max_year
      FROM membership m
      WHERE year in (2018, 2019)
      GROUP BY m.id, m.site_id
     ) mm
     ON mm.id = m.id
GROUP BY m.site_id;

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我认为通过两个级别的聚合，您可以做您想做的事情：

SELECT m.site_id, 
       SUM( m.max_year = 2019 ) as total2019, 
       SUM( m.min_year = 2018 ) as total2018,
       SUM( m.min_year = 2019 AND m.max_year = 2019 ) as new2019,
       SUM( m.min_year = 2018 and m.max_year = 2018 ) as renewals,
       SUM( m.max_year = 2018 ) as lost
FROM (SELECT m.id, m.site_id, MIN(year) as min_year, MAX(year) as max_year
      FROM membership m
      WHERE year in (2018, 2019)
      GROUP BY m.id, m.site_id
     ) mm
     ON mm.id = m.id
GROUP BY m.site_id;

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样本数据和期望的结果会有帮助。样本数据和期望的结果会有帮助。这就是我需要的。谢谢你这正是我需要的。非常感谢。