SQL> create table emp1 as select * from emp where 1=2; SQL> insert into emp1 select * from emp; 传统方式数据 SQL> insert /*+ APPEND */ into emp1 select * from emp; 直接方式数据,必须commit后才能查看数据 【实验】直接路径插入数据 SQL>
在Oracle SQL中,可以使用ROWNUM关键字来实现在分层查询中选择前N个元素的功能。以下是一个示例查询: 代码语言:sql 复制 SELECT * FROM ( SELECT column1, column2, ... FROM table_name WHERE conditions ORDER BY column_name ) WHERE ROWNUM <= N; 在上述查询中,首先执行内部的SELECT语句,该语句包含...
6 wang 0113077 物理 70 fetch n rows only 取出当前记录的前多少行 如 select row_number() over(order by user_no) from user_files fetch first 5 rows only; 分类: Oracle 好文要顶 关注我 收藏该文 微信分享 洞幺人生 粉丝- 10 关注- 0 +加关注 0 0 升级成为会员 « 上一篇: SQ...
select tname,tabtype from ( select tname,tabtype,row_number() over ( order by tname ) rn from tab ) where rn between 100 and 150; 2. 使用rownum 虚列 select tname,tabtype from ( select tname,tabtype,rownum rn from tab where rownum <= 150 ) where rn >= 100; 注释:使用序列时...
2、Infomix数据库:SELECTFIRST N*FROM TABLENAME 3、DB2数据库:SELECT *FROM (SELECT * ROW_NUMBER() OVER({ORDERBY COL1DESC})AS ROWNUMFROM TABLENAME)WHEREROWNUM <= N 或者SELECTCOLUMNFROM TABLENAMEFETCHFIRST NROWSONLY 4、SQL Server数据库:SELECTTOPN*FROM TABLENAME ...
select * from table_name fetch first 2 row only 通过上述SQL,我们可以得到相应的两条数据,通过first关键字规定住要返回的两条数据是开头的数据。 同样的,我们也可以换一种方式,得调整一下关键字,不能再用first了,需要使用Next关键字了,配合rows来实现相同的效果。
2、Infomix数据库:SELECTFIRST N*FROM TABLENAME 3、DB2数据库:SELECT *FROM (SELECT * ROW_NUMBER() OVER({ORDERBY COL1DESC})AS ROWNUMFROM TABLENAME)WHEREROWNUM <= N 或者SELECTCOLUMNFROM TABLENAMEFETCHFIRST NROWSONLY 4、SQL Server数据库:SELECTTOPN*FROM TABLENAME ...
first_load_time, invalidations, parse_calls, disk_reads, buffer_gets, rows_processed,sysdate start_time,sysdate finish_time,''>'' || address sql_address,''N'' status from v$sqlareawhere address = (select sql_address from v$session where sid = 71)24.查询表空间使用情况select a.tablespace_...
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select sid,blocking_session,LOGON_TIME,sql_id,status,event,seconds_in_wait,state,BLOCKING_SESSION_STATUSfrom v$sessionwhere event like 'enq%'and state = 'WAITING'and BLOCKING_SESSION_STATUS = 'VALID' BLOCKING_SESSION:Session identifier of the blocking session. This column is valid only if BLOCK...