--union和order by连用需要放在子查询中，否则会报错 --例如： --错误写法： select * from dept1 order by deptno union select * from dept2 order by deptno; --ORA-00933 "SQL command not properly ended" --正确写法： select * from (select * from dept1 order by deptno) union select * from (select * from dept2 order by deptno);
