查询用户下的表
select table_name from user_tables;
查询所有用户下的表(dba能看到所有用户的表,非dba只能看到自己有查询权限的表)
select owner,table_name from all_tables;
查看连接信息
select username,sid,serial# from v$session;
杀掉连接
alter system kill session '48,21633';
查询oracle版本信息
select * from v$version;
查询oracle服务名
show parameter service_name;
创建视图
CREATE OR REPLACE VIEW dept_sum_vw(name,minsal,maxsal,avgsal)
AS SELECT d.dname,min(e.sal),max(e.sal),avg(e.sal)
FROM emp e,dept d
WHERE e.deptno=d.deptno
GROUP BY d.dname;
创建物化视图
create materialized view t1_view as select id from t1;
查询表的主键(结果集的第4列)
select * from user_cons_columns
where constraint_name =
(select constraint_name from user_constraints
where table_name = 'XQ4' and constraint_type ='P');