If you’re getting an error that reads “The function ‘DENSE_RANK’ must have an OVER clause with ORDER BY” in SQL Server, it’s probably because you’re calling the DENSE_RANK() function without an ORDER BY clause.
Window functions such as DENSE_RANK() require an OVER clause, and that clause must have an ORDER BY clause. If you’re getting the above error, it’s likely that you’re providing an OVER clause, but you’re omitting the ORDER BY clause.
To fix this error, add an ORDER BY clause to the OVER clause.
Example of Error
Here’s an example of code that produces the error:
SELECT
VendorId,
ProductName,
ProductPrice,
DENSE_RANK( ) OVER (
PARTITION BY VendorId
) AS DENSE_RANK
FROM Products;Result:
Msg 4112, Level 15, State 1, Line 5 The function 'DENSE_RANK' must have an OVER clause with ORDER BY.
This error occurred because I called the DENSE_RANK() function without an ORDER BY clause. Specifically, I didn’t put an ORDER BY clause in the OVER clause.
Solution
To fix this issue, add an ORDER BY clause to the OVER clause:
SELECT
VendorId,
ProductName,
ProductPrice,
DENSE_RANK( ) OVER (
PARTITION BY VendorId
ORDER BY ProductPrice
) AS DENSE_RANK
FROM Products;Result:
VendorId ProductName ProductPrice DENSE_RANK -------- ------------------------------- ------------ ---------- 1001 Long Weight (green) 11.99 1 1001 Long Weight (blue) 14.75 2 1001 Left handed screwdriver 25.99 3 1001 Right handed screwdriver 25.99 3 1002 Sledge Hammer 33.49 1 1003 Hammock 10 1 1003 Straw Dog Box 55.99 2 1003 Chainsaw 245 3 1004 Bottomless Coffee Mugs (4 Pack) 9.99 1 1004 Tea Pot 12.45 2
This time the function worked as expected.
In this example I also used the PARTITION BY clause to partition the result set, but this is optional. We can omit the PARTITION BY clause but we can’t omit the ORDER BY clause.