Sample T-SQL stored procedure: P_DisplayProductDetails

the unit price for each product subcategory. The procedure accepts the category name as an optional input parameter. Several output parameters feed useful information back to the calling batch. Finally, the stored procedure uses structured exception handling

, as discussed in a previous tip.

Use AdventureWorks
GO

IF EXISTS (SELECT * FROM sysobjects WHERE type = 'P' AND 
       name = 'P_DisplayProductDetails')
   DROP  Procedure  P_DisplayProductDetails
GO

CREATE Procedure P_DisplayProductDetails
(@Categoryname varchar(50) = NULL,
 @MatchingRows int = NULL OUTPUT,
 @ErrorString varchar(128) = NULL OUTPUT,
 @ErrorNumber int = NULL OUTPUT)
as

BEGIN TRY

            -- Append a % so our callers don't have to know 
exact subcategory names
  if @CategoryName is null
   select @CategoryName = '%'
  else
   select @CategoryName = @CategoryName + '%'

--  Use a rank function to rank data by List Price 
over subcategory name
--  The DENSE_RANK assigns consecutive rank values

  SELECT  Production.Product.ProductID, 
     Production.Product.Name AS ProductName, 
     Production.ProductCategory.Name AS CategoryName, 
     Production.ProductSubcategory.Name AS SubcategoryName,
     Production.Product.ListPrice,
DENSE_RANK() over (Partition by 
Production.ProductSubcategory.Name ORDER BY 
   Production.Product.ListPrice DESC) as PriceRank
  FROM  Production.Product 
  INNER JOIN Production.ProductSubcategory 
ON Production.Product.ProductSubcategoryID = 
Production.ProductSubcategory.ProductSubcategoryID 
  INNER JOIN Production.ProductCategory 
ON Production.ProductSubcategory.ProductCategoryID = 
Production.ProductCategory.ProductCategoryID
  WHERE  Production.ProductCategory.Name like @CategoryName
  ORDER BY Production.ProductCategory.Name  

  select @MatchingRows = @@ROWCOUNT
 
 return 0

END TRY



BEGIN CATCH

-- LOG THE ERROR … WE MAY WANT TO SKIP THIS STEP WHILE DEBUGGING ! 
 insert dbo.Application_Error_Log (UserName, errorNumber, 
                                        errorSeverity, errorState, errorMessage)
 values (suser_sname(), ERROR_NUMBER(),ERROR_SEVERITY(), 
              ERROR_STATE(), ERROR_MESSAGE())  

 
SELECT @ErrorNumber = ERROR_NUMBER(),
   @ErrorString = ERROR_MESSAGE()
   
 RAISERROR (@ErrorString, 16,1)


END CATCH

How to debug T-SQL stored procedures

• Home: Introduction
• Part 1: Sample stored procedure
• Part 2: Where to start debugging the stored procedure
• Part 3: How to step into or run the stored procedure
• Part 4: Visual Studio debug windows

ABOUT THE AUTHOR
Joe Toscano is a SQL Server instructor, speaker and database consultant for Micro Endeavors Inc. He has worked extensively with SQL Server since version 6.5, as well as Sybase and Informix prior to that. Toscano's areas of expertise include Data Transformation Services (DTS), Integration Services (SSIS), Transact-SQL (T-SQL) programming, data warehousing, performance tuning, replication, high availability (mirroring), security, disaster recovery, upgrading, migration projects and lights-out DBA tasks.