Mysql 在SQL中按列顺序提取每月潜在客户计数？

我正试图统计每个公司每月的潜在客户数量。我可以通过以下查询在任何一个月进行查询：

MONTH 1 LEAD COUNTS
select l.companyProfileID, count(l.id) as 'Month 1 LC'
from lead l
join companyProfile cp on cp.id = l.companyProfileID
where l.createTimestamp between cp.createTimestamp and date_sub(cp.createTimestamp, INTERVAL -1 month)
group by companyProfileID

MONTH 2 LEAD COUNTS
select l.companyProfileID, count(l.id) as 'Month 2 LC'
from lead l
join companyProfile cp on cp.id = l.companyProfileID
where l.createTimestamp between date_sub(cp.createTimestamp, INTERVAL -1 month) and date_sub(cp.createTimestamp, INTERVAL -2 month)
group by companyProfileID

但我不想运行12个不同的查询来获得一年的潜在客户数量，而是想生成一个包含列的表：companyProfileID、month1lc、month2lc等等

我想这可能需要一个嵌入式select函数，但我仍在学习SQL。如何实现这一点？

您可以使用“条件聚合”，而不是运行多个查询。实际上，您将当前where条件移动到聚合函数中，以形成一个

大小写表达式

。请注意，

count（）

函数忽略空值

select 
        l.companyProfileID
      , count(case when l.createTimestamp between cp.createTimestamp 
                    and date_sub(cp.createTimestamp, INTERVAL -1 month) then 1 end) as 'Month 1 LC'
      , count(case when l.createTimestamp between date_sub(cp.createTimestamp, INTERVAL -1 month)
                    and date_sub(cp.createTimestamp, INTERVAL -2 month) then 1 end) as 'Month 2 LC'

      ... more (similar to the above)

      , count(case when l.createTimestamp between date_sub(cp.createTimestamp, INTERVAL -11 month)
                    and date_sub(cp.createTimestamp, INTERVAL -12 month) then 1 end) as 'Month 12 LC'
from lead l
join companyProfile cp on cp.id = l.companyProfileID
where l.createTimestamp between cp.createTimestamp and date_sub(cp.createTimestamp, INTERVAL -12 month)
group by companyProfileID

还请注意，“介于”要求第一个日期早于第二个日期，例如，以下内容不会返回行：

select * from t where datecol between 2018-01-01 and 2017-01-01

然而，这将起作用：

select * from t where datecol between 2017-01-01 and 2018-01-01

---

使用

分组依据执行单个查询，以获得12组值。然后“透视”数据（通过另一个查询）以获得12列。跟随我添加的标签。