Consider the following database schema:

SUPPLIER$($SName$,$ ItemName, Price$)-$ supplier SName sells item ItemName

at Price.

CUSTOMER$($CName$,$ Address$)-$ customer CName lives at Address.

ORDER$($CName$,$ SName, ItemName, Qty$)-$ customer CName has ordered

Qty of item ItemName from supplier SName.

ITEM$($ItemName$,$ Description$)-$ Information about items.

Further, suppose that you want to add the following constraint to this diagram: Every item

is supplied by some supplier. Draw the EER diagram from which the above schema

might have been derived. Specify $($a$)$ keys, $($b$)$ structural constraints, and $($c$)$ roles $($if

this is necessary$).$ For the constraints use both the traditional notation $($single$/$double lines

and numbers across the diamonds$)$ and the $($min$,$ max$)$ notation. State clearly any additional

assumptions that you made in designing the ER diagram.