I have an item, any item has type, any type has several attibutes, any attribute not common with other type of item,,,
How can I normalize this item?
Example:
Item(Item#, Item_Type, Item_Type1_Attribute1, Item_Type1_Attribute2, Item_Type1_Attribute3, Item_Type2_Attribute1, Item_Type2_Attribute2,
Item_Type3_Attribute1)

Item(1,A,A1,A2,A3,null,null,null)
Item(1,B,null,null,null,B1,B2,null)
Item(1,C,null,null,null,null,null,C1)