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最近刚在搞一个BI的项目，里面需要大量的sql 数据统计相关运用，加深了我又对SQL的理解与使用。
所以，分享几个数据统计时常用的sql 语句总结：
1. 统计各个条件下的数据
selectBatchId,sum(CardSum) 总金额,sum(case when Status=1 then CardSum else 0 end) as 已使用,sum(case when Status=2 then CardSum else 0 end) as 已冻结 from GiftCard group by BatchId
2. 统计每日,每月,每年的数据
select year(AddTime) 年,month(AddTime) 月,day(AddTime) 日,COUNT(1) 数量,sum(CardSum) 销售合计from GiftCardgroup by year(AddTime),month(AddTime),day(AddTime)
3. 某列去重统计
select COUNT(BatchId),COUNT(distinct BatchId),COUNT(distinct BatchName)from GiftCard
4. 行转列
SELECT *FROM (SELECT BatchName, CardSum as TotAmount FROM GiftCard) as sPIVOT( SUM(TotAmount)FOR BatchName IN (zx测试商品, test新人优惠券,测试高考大放送))AS MyPivot
5. 得到表中最小的未使用的ID号
SELECT (CASE WHEN EXISTS(SELECT * FROM GiftCard b WHERE b.Id = 1) THEN MIN(Id) + 1 ELSE 1 END) as Id FROM GiftCardWHERE NOT Id IN (SELECT a.Id - 1 FROM GiftCard a)
6. 查询某一列数据不重复的数量
select *
from GiftCard a
where not exists(select 1 from GiftCard where BatchName=a.BatchName and ID<a.ID)
7.按年统计1月到12个月的销量
select year(AddTime) as '年',SUM(case when MONTH(AddTime)=1 then CardSum else 0 end ) as '一月',SUM(case when MONTH(AddTime)=2 then CardSum else 0 end ) as '二月',SUM(case when MONTH(AddTime)=3 then CardSum else 0 end ) as '三月',SUM(case when MONTH(AddTime)=4 then CardSum else 0 end ) as '四月',SUM(case when MONTH(AddTime)=5 then CardSum else 0 end ) as '五月',SUM(case when MONTH(AddTime)=6 then CardSum else 0 end ) as '六月',SUM(case when MONTH(AddTime)=7 then CardSum else 0 end ) as '七月',SUM(case when MONTH(AddTime)=8 then CardSum else 0 end ) as '八月',SUM(case when MONTH(AddTime)=9 then CardSum else 0 end ) as '九月',SUM(case when MONTH(AddTime)=10 then CardSum else 0 end ) as '十月',SUM(case when MONTH(AddTime)=11 then CardSum else 0 end ) as '十一月',SUM(case when MONTH(AddTime)=12 then CardSum else 0 end ) as '十二月'from GiftCardgroup by year(AddTime)
