Order by keyword syntax problems encountered in SQL Server learning

background
At night sql Examples seen during the basic tutorial , Write it on the computer and keep reporting errors

select product_id,product_name,sale_price,        sum(sale_price) over(partition by product_type order by product_price) as current_sum    from product;select product_id,product_name,sale_price,        avg(sale_price) over(order by product_id) as current_avg    from product;

Operation results and error reporting contents

news 102, Level 15, state 1, The first 2 That's ok
'order' There are grammar errors nearby .
The error contents of both statements have been order There are grammatical errors at , But I don't know what's going on . I hope you can get an answer .

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Take the answer ：

Your mistake is inevitable , because COUNT(),SUM(),AVG(),MAX(MIN() All belong to aggregate functions , Aggregate windowing function can only use PARTITION BY Clause or without any statement ,ORDER BY Cannot be used with aggregate windowing function .　　
Grammatical structure ： Aggregate functions ( ) OVER ( [ <partition_by Clause > ] )

So you used order by It's wrong. , You can refer to this article for more information , I hope it helps you

sqlserver Middle window functions and OVER() function _ Take dreams as horses Not to lose time -CSDN Blog Reference resources ：https://blog.csdn.net/qq_41805514/article/details/81772182 https://blog.csdn.net/qq_27997957/article/details/82383328 One 、OVER() function 　　 Grammatical structure ：OVER([ PARTITION BY... ][ ORDER BY... ] ...https://blog.csdn.net/ABC13222880223/article/details/91982829

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