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May 21, 2020
sql server row_number example
sql server row number by partition
sql server row_number over partition by order by
In this video we will discuss Row_Number function in SQL Server. This is continuation to Part 108. Please watch Part 108 from SQL Server tutorial before proceeding.
Row_Number function
Introduced in SQL Server 2005
Returns the sequential number of a row starting at 1
ORDER BY clause is required
PARTITION BY clause is optional
When the data is partitioned, row number is reset to 1 when the partition changes
Syntax : ROW_NUMBER() OVER (ORDER BY Col1, Col2)
Row_Number function without PARTITION BY : In this example, data is not partitioned, so ROW_NUMBER will provide a consecutive numbering for all the rows in the table based on the order of rows imposed by the ORDER BY clause.
SELECT Name, Gender, Salary,
ROW_NUMBER() OVER (ORDER BY Gender) AS RowNumber
FROM Employees
Please note : If ORDER BY clause is not specified you will get the following error
The function ‘ROW_NUMBER’ must have an OVER clause with ORDER BY
Row_Number function with PARTITION BY : In this example, data is partitioned by Gender, so ROW_NUMBER will provide a consecutive numbering only for the rows with in a parttion. When the partition changes the row number is reset to 1.
SELECT Name, Gender, Salary,
ROW_NUMBER() OVER (PARTITION BY Gender ORDER BY Gender) AS RowNumber
FROM Employees
Use case for Row_Number function : Deleting all duplicate rows except one from a sql server table.
Discussed in detail in Part 4 of SQL Server Interview Questions and Answers video series.
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Very good tutorial Venkat 🙂 thank you
man you r hell of a teacher thanks
Is there a way to get a rownumber, by gender, such that all in one gender is 1 and the next gender all has a rownumber of two and if there was a third gender then it would all be 3? This isn't really a rownumber anymore but a grouping number to show which 'gender' we are processing.
Great explanation! Thx!
Hey, Kudvenkat. Just want to leave a message to you. Your tutorial is the best I've ever seen. Thank you so much!
Hey guys help me how to find odd rows and even rows
Thanks Venkat it was well don Tutorial
You are amazing!
Thank you Venkat. You are helping me a lot. Please make a video how we can rollback our database to a given point.
Wow. You explain like a G!!! Gang gang. God bless
God bless you!
me si sirvio bastante, a pesar de estar en ingles , logre enteder la idea del ROW NUMBER . Muchas gracias
I was looking for this thank you so much
Thank u sir.
thanx alot your videos is helping me
Cystal clear explanation!
thank you Venkat Sir
Great!! Thanks!
This helped me a lot, thanks!
very helpful thanks kudvenkat!
well explained
Hi, thanks for the video, this seems like a very simple function, i have tried it and it seems like its working by its actually returning an empty column, this is my exact code: ROW_NUMBER() OVER (PARTITION BY orddet_nl.invnum ORDER BY orddet_nl.invnum ASC) AS LineReference,
i dont get any error messages or anything, but it just brings an empty column, any ideas why?
Thanks
very good video, flawless
Great video. Could you also use Row_Number as a means to replace a cursor? How would that effect query performance?
I am using SQL community version 5.5.57, Could you please tell me why i am getting below error? Thanks in advance:)
mysql> select * from userinfo;
+———+———-+———+
| loginId | password | access |
+———+———-+———+
| z011111 | A1 | User |
| z021720 | ram99 | Manager |
| z021721 | demo | User |
+———+———-+———+
5 rows in set (0.00 sec)
mysql> select *, row_number() over(order by loginId) as rowNumber from userinfo;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(order by loginId) as rowNumber from userinfo' at line 1
GREAT TEACHER! I have been using your videos to reference SQL where I have no clues. Thanks for all your hard works!
Wonderful
I have seen several of you videos that reference Partition. What does that do?
Row number rules ! And Venkat rules! You are the best teacher on youtube and in the whole world. I saw all your videos from SQL Server tutorial. Thank U for educating community! God bless you.
can we use one more where clause with row number…?
Really well explained. Thank you. I really appreciate that you explained the use of it, more people should add that 'cause it's not always clear.
Hi Venkat,
I have data that has following rows….
2934046 Kellogg’s Share Your Breakfast 74672 2407522 Kellogg?s Share Your Breakfast ACTIVE 2015-09-01 9999-12-31
2934046 Kellogg?s Share Your Breakfast 74672 2407522 Kellogg?s Share Your Breakfast ACTIVE 2015-09-01 9999-12-31
You can see that both rows are the same except for the question mark in the second row. I have to remove such rows from my table. I was trying to use row_number for this, but it doesn't work. Is there any way i can rank such rows based on the characters in my second column…
What if you only want to return the row with the max row number?
Great channel, please keep doing these videos. You are the teacher i never had.
I have sent an email and still waiting for reply. Thumbs up for this video.