Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
420 views
in Technique[技术] by (71.8m points)

sql server - SQL Row_Number() function in Where Clause without ORDER BY?

I found a bunch of questions on this topic with nice solutions but none of them actually deal with what to do if the data is not to be ordered in one specific way. For instance, the following query:

WITH MyCte AS 
(
    select   employee_id,
             RowNum = row_number() OVER ( order by employee_id )
    from     V_EMPLOYEE 
    ORDER BY Employee_ID
)
SELECT  employee_id
FROM    MyCte
WHERE   RowNum > 0

works well if the data is to be ordered by employee_id. But what if my data does not have any specific order but the row numbers themselves act as an ID? My goal is to write a query like this (with the Row_Number() function having no ORDER BY clause):

WITH MyCte AS 
(
    select   employee_id,
             RowNum = row_number() OVER ( <PRESERVE ORIGINAL ORDER FROM DB> )
    from     V_EMPLOYEE 
    ORDER BY Employee_ID
)
SELECT  employee_id
FROM    MyCte
WHERE   RowNum > 0

EDIT: Upon Googling, I figured out that this is not really possible. Can some suggest a workaround for this?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Just in case it is useful to someone else. I just figured it out from elsewhere:

WITH MyCte AS 
(
    select   employee_id,
             RowNum = row_number() OVER (ORDER BY (SELECT 0))
    from     V_EMPLOYEE 
    ORDER BY Employee_ID
)
SELECT  employee_id
FROM    MyCte
WHERE   RowNum > 0

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...