TSQL - Try and catch and raise error

-- Declarations

declare @error_message nvarchar(2000);

set @error_message = null;

declare @error_severity nvarchar(2000);

set @error_severity = null;

declare @error_state nvarchar(2000);

set @error_state = null;

declare @error_number int;

set @error_number = null;

-- Try

BEGIN TRY 

       -- Do something here

END TRY 

-- Catch

BEGIN CATCH 

       -- Available error variables

       /*SELECT

              ERROR_NUMBER() 

              , ERROR_SEVERITY() 

              , ERROR_STATE() 

              , ERROR_PROCEDURE() 

              , ERROR_LINE() 

              , ERROR_MESSAGE() 

       ; */

       -- Error number

       set @error_number = ERROR_NUMBER();                   

       -- Capture the error message, severity and state

       set @error_message = ERROR_MESSAGE();

       set @error_severity = ERROR_SEVERITY();

       set @error_state = ERROR_STATE();

       -- Debug

       print 'ERROR CAUGHT -> ' + @error_message;

       -- Raise error, so the job that will call this procedure launches a notification

       RAISERROR (

                     @error_message, -- Message text. 

                     @error_severity, -- Severity. 

                     @error_state -- State. 

              );

END CATCH