虽然网上例子很多,但是试过多种办法都无效,原代码出处: https://blog.csdn.net/qyshibb/article/details/73332075 这个例子简单有效 select p.* from (select * from tablename t order by t.maxnum desc) p where rownum = 1
oracle Insert 一次插入多条记录有两种方法: 1)Insert All Into table_name values ... insert all into table_name values(') into table_name values(') from dual; 2)Insert Into table_name select from insert into table1_name ' from table2_name t1 '
例如student表: studentID studentName studentScore 01 Alice 90 02 Bill 95 03 Cindy 100 一.拼接多个字段的值 select studentID+‘-’+studentName+'-'+studentScore AS studentInfo from student 结果: 二.一个字段多条记录的拼接 select stuff((select '|'+studentName from student for xm
oracle中怎么查询各组中最新的一条记录呢?比如说现在有一个表中几条数据如下: 有两种写法:写法一:over partition by 分析函数 SELECT * FROM (select ID_,COMPANY_NAME,USAGE_RATE,DETECTION_RATE,ACCEPTABILITY_RATE,CREATE_TIME,MAX(CREATE_TIME) over(partition by COMPANY_NAME) as "atime" from SPEC_RATE_
如student表: studentID studentName studentScore 01 Alice 90 02 Bill 95 03 Cindy 100 一.拼接多个字段的值 select studentID+‘-’+studentName+'-'+studentScore AS studentInfo from student 结果: 二.一个字段多条记录的拼接 select stuff((select '|'+studentName from student for xml p
删除同一组内其他记录 DELETE from memactivities a where exists(select 1 FROM (select Uuid,ci_no,lst_upd_ts,ROW_NUMBER() OVER(PARTITION BY Uuid order by ci_no) rn from ics.memactivities where uuid is not null)b where a.Uuid=b.Uuid AND a.lst_upd_ts=b.lst_upd_ts a
11g里面用listagg: select listagg(name,',') within (order by id) from table 10g里面用wm_concat:select wm_concat(name) from table wm_concat是undocument的listagg是11g document的
with temp as( select 'China' nation ,'Guangzhou' city from dual union all select 'China' nation ,'Shanghai' city from dual union all select 'China' nation ,'Beijing' city from dual union all select 'USA' nation ,'New York' city from dual union all se
查询用户编号为1165的所有数据: ,,,,,) ' order by JianCeID desc 查询用户编号为1165且监测参数为(1,2,7,15,19,20)的最新数据: select * from T_JianKangJC_JianCeSJ a where exists( select * from ( ,,,,,) group by JianCeCSID ) x where x.JianCeCSID=a.JianCeCSID and a.JianCeSJ=x.FTime )
有些时候,我们希望同时更新表中的多条记录,但更新的值不一样. declare @i int declare @j int declare @phone varchar(20) set @j=1 select @i=count(*) from LatestLocation DECLARE L_cursor CURSOR FOR SELECT Phone FROM LatestLocation OPEN L_cursor while @j<=@i begin FETCH NEXT FROM L_cu
在Oracle怎样查询表中的top10条记录呢? select * from test where rownum <=10 下面是关于rownum的介绍 ================================ Rownum和row_number() over()的使用 ROWNUM是Oracle从8开始提供的一个伪列,是把SQL出来的结果进行编号,始终从1开始,常见的用途就是用来分页输出. 比如 SELECT * FROM torderdetail a WHERE ROWNUM <=
在Oracle怎样查询表中的top10条记录呢? select * from test where rownum <=10 ----说明:rownum只能用于<或<=运算,如果要用>运算符就要用到嵌套查询. 下面是关于rownum的介绍 ================================ Rownum和row_number().over()的使用 ROWNUM是Oracle从8开始提供的一个伪列,是把SQL出来的结果进行编号,始终从1开始,常见的用途就是用来分
mysql 批量更新与批量更新多条记录的不同值实现方法 在mysql中批量更新我们可能使用update,replace into来操作,下面详细介绍mysql批量更新与性能. 批量更新 mysql更新语句很简单,更新一条数据的某个字段,一般这样写: UPDATE mytable SET myfield = 'value' WHERE other_field = 'other_value'; 如果更新同一字段为同一个值,mysql也很简单,修改下where即可: UPDATE mytable SE