Sql 中 Exists 的应用

最新推荐文章于 2025-09-05 18:19:02 发布

原创最新推荐文章于 2025-09-05 18:19:02 发布 · 415 阅读

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#sql #scala

本文探讨了SQL查询中使用distinct关键字的选择性过滤，并通过连接不同数据源进行数据整合，重点介绍了如何通过子查询实现数据计数并筛选出重复项。内容涵盖了数据清理和聚合分析的关键步骤。

select distinct ttt.PRJ,ttt.CCTR from (
select distinct
substring(gl06001,23,6) CCTR, substring(gl06001,34,3) PRJ--, '08' as Entity
from [cnbj1scala01].[ScalaDB_Trading].[dbo].GL060811
where substring(gl06001,34,3)!='' and substring(gl06001,23,6)!=''
--order by CCTR ,PRJ
union all

select distinct
substring(gl06001,23,6) CCTR, substring(gl06001,34,3) PRJ--, '03' as Entity
from [cnbj1scala01].[ScalaDB_Trading].[dbo].GL060311
where substring(gl06001,34,3)!='' and substring(gl06001,23,6)!=''
--order by CCTR ,PRJ
) as ttt
where exists (

select tt.CCTR ,Count(tt.CCTR ) from (
select distinct t.CCTR ,t.PRJ from (
select distinct
substring(gl06001,23,6) CCTR, substring(gl06001,34,3) PRJ--, '08' as Entity
from [cnbj1scala01].[ScalaDB_Trading].[dbo].GL060811
where substring(gl06001,34,3)!='' and substring(gl06001,23,6)!=''
--order by CCTR ,PRJ
union all