问题描述
我使用oracle 11g.下面的行顺序是空的
i use oracle 11g.what does the line order by null means in the following
select f_value,row_number() over (order by null) as id
from tableName"
推荐答案
ROW_NUMBER()的OVER()子句需要ORDER BY
使用ORDER BY NULL是一种解决方法，它满足了语法要求，但实际上并未更改数据的顺序.实际上，这是完全不订购的指令.
using ORDER BY NULL is a workaround that satifies the syntax requirement but does not actually change the order of the data. In effect it is an instruction to not order at all.
NB :有些人(包括我自己)更喜欢使用SELECT 1而不是SELECT NULL，但是效果没有差别.
N.B.: some (myself included) prefer to use SELECT 1 instead of SELECT NULL but there is no difference in effect.
底线:不太好，但是可以.
Bottom line: not great, but it works.
提示:TSQL不允许直接使用SELECT 1，但是您可以使用(SELECT 1)
tip: TSQL does not permit the direct use of SELECT 1, but you may use (SELECT 1)
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