T-SQL Analyzer

# SQL Server Rule: SRP0009 | | | |----|----| | Assembly | SqlServer.Rules | | Namespace | SqlServer.Rules.Performance | | Class | AvoidColumnFunctionsRule | ## Rule Information | | | |----|----| | Id | SRP0009 | | Friendly Name | Filtering on calculated value | | Category | Performance | | Ignorable | true | | Applicable Types | Procedure | | | Scalar Function | | | Table Valued Function | | | View | ## Description Avoid wrapping columns within a function in the WHERE clause. (Sargable) ## Summary Avoid wrapping columns within a function in the WHERE clause. This affects sargability. ### Examples ```sql CREATE PROCEDURE dbo.UpperFunction AS SET NOCOUNT ON; SELECT user_name FROM dbo.MyTable WHERE UPPER(first_name) = 'NATHAN'; -- SRP0009 ``` ### Remarks When a WHERE clause column is wrapped inside a function, the query optimizer does not see the column and if an index exists on the column, the index will not to be used. _{^{Generated by a tool}}