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sql 查询时如何去掉重复的部分写在whErE中

关键字Distinct 去除重复 如下列SQL,去除Test相同的记录; select distinct Test from Table 如果是要删除表中存在的重复记录,那就逻辑处理,如下: select Test from Table group by Test having count(test)>1 先查询存在重复的数据,后面...

条件写成where _identify (between 1 and 29) and (between 31 and 32)是错误的,这样的条件得不到任何符合条件的记录。 要剔除部分记录,可以用条件不等于或者not in,例如: where _identify between 1 and 32 and not in (30)

select col1,col2,col3 from (select col1,col2,col3, row_number() over(partition by col1 order by col2 desc) rn from table_name ) a where rn=1

where后加多个条件可以用and来连接。 如,student表中有如下数据: 现在要查,sex为男,age为20的那些数据,可用如下语句: select * from student where sex='男' and age=20;结果截图:

select distinct SFM_BH as 住院号,SFM_XM as 姓名,SFM_JZBZ 标志, SFM_JF 缴费合计,SFM_DF 费用合计,SFM_YE 余额 from (select SFD_BH,SFD_CZY,SFD_RQ,SFD_ZFLB,SFD_ZY from ZY_SFD where SFD_JDLB=0 and SFD_BZ=1 and DATEDIFF(Day, SFD_RQ, '...

1、查找表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断 select * from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1) 2、删除表中多余的重复记录,重复记录是根据单个...

方法一按照多条件重复处理: delete tmp from( select row_num = row_number() over(partition by 字段,字段 order by 时间 desc) from 表 where 时间> getdate()-1 ) tmp where row_num > 1 方法二按照单一条件进行去重: delete from 表 wher...

select table1.name,table2.*fromtable1,table2 where table1.userid=table2.userid and table2.id in(select min(id) as id from table1,table2 where table1.userid=table2.userid)

select * from table t1 where not exists (select 1 from table t2 where t1.colA=t2.colA and t1.colB=t2.colB and t1.colC=t2.colC and t2.rowid>t1.rowid) 大概酱紫吧。好久没用oracle了

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