T-SQL Where Clause Case Statement Optimization (optional parameters to StoredProc)

Question

I\'ve been battling this one for a while now. I have a stored proc that takes in 3 parameters that are used to filter. If a specific value is passed in, I want to filter on that

Answer 1

if you are running SQL Server 2005 or above you can use IFs to make multiple version of the query with the proper WHERE so an index can be used. Each query plan will be placed in the query cache.

also, here is a very comprehensive article on this topic:

Dynamic Search Conditions in T-SQL by Erland Sommarskog

it covers all the issues and methods of trying to write queries with multiple optional search conditions

here is the table of contents:

  Introduction
      The Case Study: Searching Orders
      The Northgale Database
   Dynamic SQL
      Introduction
      Using sp_executesql
      Using the CLR
      Using EXEC()
      When Caching Is Not Really What You Want
   Static SQL
      Introduction
      x = @x OR @x IS NULL
      Using IF statements
      Umachandar's Bag of Tricks
      Using Temp Tables
      x = @x AND @x IS NOT NULL
      Handling Complex Conditions
   Hybrid Solutions – Using both Static and Dynamic SQL
      Using Views
      Using Inline Table Functions
   Conclusion
   Feedback and Acknowledgements
   Revision History