When working with SQL Server, it’s important to understand the limitations and best practices for using the ORDER BY clause in views. In this blog post, we will explore the reasons behind the error that occurs when using ORDER BY in views, the automatic generation of TOP (100) PERCENT, and potential solutions to this issue.

Reason for Error

The error message clearly states that the ORDER BY clause is invalid in views, inline functions, derived tables, subqueries, and common table expressions, unless TOP, OFFSET, or FOR XML is also specified. This limitation exists because the optimizer only follows the ORDER BY within the same scope or the same SELECT/UPDATE/DELETE statement. Ordering after the scope of the view would result in wasted efforts, as the final resultset of the query follows the final ORDER BY or outer query’s order. Therefore, ORDER BY is not allowed in views.

Reason for Auto Generated TOP (100) PERCENT

To overcome the error mentioned above, one popular workaround is to use TOP (100) PERCENT in the view. This allows the use of ORDER BY in the query and gives the impression that the error has been resolved. However, this is incorrect. When TOP (100) PERCENT is used, the result is not guaranteed, and it is ignored in the query where the view is used. The automatic addition of TOP (100) PERCENT when creating a view in SQL Server Management Studio (SSMS) with an ORDER BY clause is a default behavior.

Potential Solutions

If ORDER BY is not necessary for the business logic of the view, it should be avoided altogether. In most cases, ORDER BY should be used in the outer query to present the result in the desired order. The use of TOP 100 PERCENT with ORDER BY is unnecessary and can be removed from the view before using it in any query or procedure. However, if there is a clear business need to use TOP with a percentage lower than 100 (e.g., TOP 10 PERCENT or TOP 50 PERCENT), it is valid to use ORDER BY in the view.

It’s important to note that this topic is complex and cannot be fully covered in a single blog post. For further information and a more detailed explanation, I recommend reading the blog posts mentioned in this article.

Thank you for reading! I hope this post has provided you with a better understanding of the use of ORDER BY in SQL Server views. If you have any comments or suggestions, please feel free to share them.