OR Operator Short-circuit in SQL Server

Question

I want to consult SQL Server OR short-circuit

Code:

   DECLARE @tempTable table
      (
         id int
      )
      INSERT @tempTable(id) values(1         


        

Answer 1

Just stumbled over this question, and had already found this blog-entry: http://rusanu.com/2009/09/13/on-sql-server-boolean-operator-short-circuit/

The SQL server is free to optimize a query anywhere it sees fit, so in the example given in the blog post, you cannot rely on short-circuiting.

However, a CASE is apparently documented to evaluate in the written order - check the comments of that blog post.