I work on sql server 2012 i see constrain but i don't know what is meaning
ALTER TABLE [Parts].[TradeCodes] ADD CONSTRAINT [UC_PartCode] UNIQUE NONCLUSTERED ( [PartID] ASC, [CodeTypeID] ASC, [PartLevel] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] GO
what is benfit from code above