All ROW_NUMBER() and it’s partner OVER does is to add a virtual row number to the start of each row returned. That’s it. Nothing more dramatic than that. Take a look at this query:

SELECT CallID, ROW_NUMBER() OVER (ORDER BY ID) AS Row
FROM CallRecords

which returns:

CallID    Row
101        1
102        2
103        3
104        4
105        5
106        6
107        7
108        8
109        9
110        10

(10 row(s) affected)

As you can see, has created a new ‘virtual’ column named ‘Row’ and filled it with sequential row numbers. Breaking this query down, we can see what each individual part does:

SELECT CallID : Returns the data from the CallID Column from my table
ROW_NUMBER() : Works the magic to return a row number
OVER (ORDER BY ID) : This determines the order of the data that is returned BEFORE the row number is added
AS Row : gives the column generated by ‘ROW_NUMBER() OVER (ORDER BY ID)’ the name ‘Row’
FROM CallRecords : Get the data from my CallRecords tables

Now let’s expand this query to return just the rows between 5 and 9 by wrapping it in a bit of extra SQL:

SELECT CallID, Row FROM
( SELECT CallID, (ROW_NUMBER() OVER (ORDER BY ID))
AS Row FROM calldatarecords ) Rows
WHERE Row BETWEEN 5 and 9

And that’s it! Have fun!