我写了个select * from courses union select * from minors order by 1 在SQL/PLUS 里面运行,
可是我写了select * from courses union select * from minors order by desc 系统却提示:ORA-00936:缺失表达式初学这个,书上没写ORDER BY ASC 与ORDER BY 1 的区别?
想请教下,
可是我写了select * from courses union select * from minors order by desc 系统却提示:ORA-00936:缺失表达式初学这个,书上没写ORDER BY ASC 与ORDER BY 1 的区别?
想请教下,
对第一个字段进行升序排序select * from courses union select * from minors order by desc
错误,加个表中存在(或转换过后的)的字段名(或转换过后的)
例如
select * from courses union select * from minors order by id desc select substr(id , 1 , 2) new_id, * from courses union select * from minors order by substr(id , 1 , 2) desc
ORDER BY ASC应该没有这样写法,ORDER BY 后面不是字段就是数字,
可以ORDER BY 1 ASC 或者ORDER BY COL1 ASCASC表示按升序排序,DESC表示按降序排序