declare @SqlStr as nvarchar(max)

  set @SqlStr=N'Merge Into [Categories] t

  USING(VALUES (9,''rice'',''main food'',null))

  AS s ([CategoryID],[CategoryName],[Description],[Picture])

  on t.[CategoryID]=s.[CategoryID]

  When Matched Then Update Set t.[CategoryName]=s.[CategoryName],

                               t.[Description]=s.[Description],

                               t.[Picture]=s.[Picture]

  When Not Matched Then Insert ([CategoryName],[Description],[Picture])

                        values(s.[CategoryName],s.[Description],s.[Picture]);'

  exec sp_executesql @SqlStr