查看表结构 select*from user_tab_columns where table_name='表名';查看表主键 select a.constraint_name,a.column_name from user_cons_columns a,user_constraints b where a....查询表结构演示：查询表主键演示：喜欢的点个赞❤吧！
通过 sql查询当前数据库所有表空间的使用率：set line222 col pagesize1000 col TABLESPACE_NAME for a40 select tbs_used_info.tablespace_name,tbs_used_info.alloc_mb,tbs_used_info.used_mb,tbs_used_info.max_mb,tbs_used_info.free_...
子查询 子查询要解决的问题，不能一步求解 分为：单行子查询-多行子查询 语法：SELECT select_list FROM table WHERE expr operator(SELECT select_list FROM table);子查询（内查询）在住查询之前一次执行完成 子查询的记过被主查询使用...
（杀除对应的session）分析最耗资源的sql语句:查看oracle最耗资源的sid和用户：select sid,serial#,username,status,last_call_et from v$session where status='ACTIVE' and username is not null order by last_call_et desc;查看上面...
查询及删除 重复记录的SQL语句 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...
SQLServer查询分页语句：查询语句1：select*from(select row_number()over(order by stuno asc)as row_number,*from studenttb where stuclass='2')as tl where tl.row_number between pagesize*(pagenumber-1)and pagesize*pagenumber;...
