http://localhost:1313/tags/sql-server/ Recent content in SQL Server on Yunier's Wiki Hugo en Sat, 13 Nov 2021 00:00:00 +0000 http://localhost:1313/post/2021/sort-functions-are-nondeterministic/ Sat, 13 Nov 2021 00:00:00 +0000 http://localhost:1313/post/2021/sort-functions-are-nondeterministic/ <p>When building a Web API, RESTful or GraphQL, you may want to expose some functionality that allows a client application to sort data.</p> <p>From my experience, this is often not implemented correctly. Many developers fail to realize that sorting should always be sort plus one. The plus one is a unique value, like a primary key or identifier. The reason for this is that sorting in most databases, <a href="https://docs.microsoft.com/en-us/sql/t-sql/queries/select-order-by-clause-transact-sql?redirectedfrom=MSDN&view=sql-server-ver15#arguments">like SQL Server</a>, is nondeterministic, meaning the sort function may return different results each time they are called with a specific set of input values even if the database state that they access remains the same.</p>