Defensive Database Programming - Red Gate Software

Chapter 6: Common Problems with Data Integrity) ;GOINSERT INTO dbo.Items(ItemLabel,BoxLabel,WeightInPounds,Barcode)VALUES ('Sleeping Mat','Camping Gear',1,NULL) ;Listing 6-29: The CHECK constraint UNQ_Items_Barcode allows us to insert morethan one row with a NULL barcode.Listing 6-30 verifies that we can INSERT items with NOT NULL barcodes, as long as wedo not INSERT duplicates.INSERT INTO dbo.Items(ItemLabel,BoxLabel,WeightInPounds,Barcode)VALUES ('Big Flashlight','Camping Gear',2,'12345678') ;GO182