在A表中存在一个字段“AccountId”,而且不同记录之间的“AccountId”值有可能会相同,现在就是需要查询出在该表中的各记录之间,“AccountId”值存在重复的项,这里count记录该字段重复的记录数(此处只针对该字段是否重复进行查询):Select AccountId,Count(*) From A Group By AccountId Having Count(*) > 1 如果查询多个字段也相同大则如下:Select AccountId,Name,Count(*) From
1.在面试的时候碰到一个 问题,就是让写一张表中有id和name 两个字段,查询出name重复的所有数据,现在列下: select * from xi a where (a.username) in (select username from xi group by username having count(*) > 1) 2.查询出所有数据进行分组之后,和重复数据的重复次数的查询数据,先列下: select count(username) as '重复次数',username from
with a as( select nsr.zgswj_dm, count(distinct nsr.djxh) cnt, 1 z from hx_fp.fp_ly fp, hx_dj.dj_nsrxx nsr where nsr.djxh = fp.djxh and nsr.nsrzt_dm = '03' and fp.lrrq >= date '2018-03-01' and fp.lrrq <= date '2018-04-01' AND nsr.ZGSWSKFJ_DM LIKE '13
select * from DB_PATCH awhere lower(a.db_name) in (select lower(db_name) from DB_PATCH group by lower(db_name) having count(*) > 1) delete from DB_PATCH awhere lower(a.db_name) in (select lower(db_name) from DB_PATCH group by lower(db_name) having co
用于直接drop掉表的情况(plsql developer直接删掉表就是drop操作) 查删除的表select object_name,original_name,partition_name,type,ts_name,createtime,droptime from recyclebin;同时查出的有表的主键.索引等等,只需闪回表,其他的也随之恢复 闪回flashback table tablename to before drop;
--查询所有数据库USE mastergoselect [name] from [sysdatabases] order by [name] --查询其中一个数据库test,就可以得到这个数据库中的所有的表名了,语句如下: USE testgo select [id], [name] from [sysobjects] where [type] = 'u' order by [name] --查出v_lyb这个表中所有的字段select [name] from [syscolumns] wher
sp_help sys_user sp_columns sys_user --表结构 THEN obj.name ELSE '' END AS 表名, col.colorder AS 序号 , col.name AS 列名 , ISNULL(ep.[value], '') AS 列说明 , t.name AS 数据类型 , col.length AS 长度 , ) AS 小数位数 , THEN '√' ELSE '' END AS 标识 , FROM dbo.sysindexes si IN
linux环境将*.dmp文件导入数据库时,df -h 发现测试环境虚拟机空间不足,而数据文件xxx.dbf所占空间达到40G左右,果断删除表空间重建在导入. 一.查出存储数据表空间名称 select file_name,tablespace_name,autoextensible from dba_data_files: 二.删除表空间及其内容 alter tablespace USERS OFFLINE; drop tablespace including contents and d