Oracle查询语句

Oracle查询语句（用户角色、所有表格）

1.查看所有用户：    select * from dba_users;       select * from all_users;       select * from user_users;2.查看用户或角色系统权限(直接赋值给用户或角色的系统权限)：    select * from dba_sys_privs;       select * from user_sys_privs; (查看当前用户所拥有的权限)3.查看角色(只能查看登陆用户拥有的角色)所包含的权限    sql>select * from role_sys_privs;4.查看用户对象权限：    select * from dba_tab_privs;       select * from all_tab_privs;       select * from user_tab_privs;5.查看所有角色：    select * from dba_roles;6.查看用户或角色所拥有的角色：    select * from dba_role_privs;       select * from user_role_privs;7.查看哪些用户有sysdba或sysoper系统权限(查询时需要相应权限)    select * from V$PWFILE_USERS8.SqlPlus中查看一个用户所拥有权限    SQL>select * from dba_sys_privs where grantee='username';其中的username即用户名要大写才行。比如：    SQL>select * from dba_sys_privs where grantee='TOM';9、Oracle删除指定用户所有表的方法    select 'Drop table '||table_name||';' from all_tables    where owner='要删除的用户名(注意要大写)';10、删除用户    drop user user_name cascade;    如：drop user SMCHANNEL CASCADE11、获取当前用户下所有的表：select table_name from user_tables;12、删除某用户下所有的表数据: select 'truncate table  ' ||           table_name from user_tables;13、禁止外键    ORACLE数据库中的外键约束名都在表user_constraints中可以查到。其中constraint_type='R'表示是外键约束。    启用外键约束的命令为：alter table table_name enable constraint constraint_name     禁用外键约束的命令为：alter table table_name disable constraint constraint_name    然后再用SQL查出数据库中所以外键的约束名：    select 'alter table '||table_name||' enable constraint '||constraint_name||';' from user_constraints where constraint_type='R'    select 'alter table '||table_name||' disable constraint '||constraint_name||';' from user_constraints where constraint_type='R'14、ORACLE禁用/启用外键和触发器--启用脚本    SET SERVEROUTPUT ON SIZE 1000000    BEGIN    for c in (select 'ALTER TABLE '||TABLE_NAME||' ENABLE CONSTRAINT '||constraint_name||' ' as v_sql from user_constraints where CONSTRAINT_TYPE='R') loop    DBMS_OUTPUT.PUT_LINE(C.V_SQL);    begin     EXECUTE IMMEDIATE c.v_sql;     exception when others then     dbms_output.put_line(sqlerrm);     end;    end loop;     for c in (select 'ALTER TABLE '||TNAME||' ENABLE ALL TRIGGERS ' AS v_sql from tab where tabtype='TABLE') loop     dbms_output.put_line(c.v_sql);     begin     execute immediate c.v_sql;    exception when others then     dbms_output.put_line(sqlerrm);     end;    end loop;    end;    /     commit;--禁用脚本    SET SERVEROUTPUT ON SIZE 1000000    BEGIN    for c in (select 'ALTER TABLE '||TABLE_NAME||' DISABLE CONSTRAINT '||constraint_name||' ' as v_sql from user_constraints where CONSTRAINT_TYPE='R') loop    DBMS_OUTPUT.PUT_LINE(C.V_SQL);    begin     EXECUTE IMMEDIATE c.v_sql;     exception when others then     dbms_output.put_line(sqlerrm);     end;    end loop;     for c in (select 'ALTER TABLE '||TNAME||' DISABLE ALL TRIGGERS ' AS v_sql from tab where tabtype='TABLE') loop     dbms_output.put_line(c.v_sql);     begin     execute immediate c.v_sql;    exception when others then     dbms_output.put_line(sqlerrm);     end;    end loop;    end;    /    commit;