Design an Entity$-$Relationship diagram for the Auction database.

$-$ Draw a diagram for three levels of abstraction

$1.$ Conceptual

$2.$ Logical

$3.$ Physical

$-$ Identify

$1.$ entity names

$2.$ relationships

$3.$ attributes and data types

$-$ Identify relationship types

$1.$ Many$-$to$-$many $($M:M$)$

$2.$ One$-$to$-$many $(1$:M$)$

$3.$ One$-$to$-$one $(1$:$1)$

$4.$ Resolve M:M relationship $($for Physical data model$)$

$5.$ Decompose composite attributes

$6.$ Identify subtypes and supertype

$7.$ Avoid Synonyms and Homonyms

Lab Task:

Consider an online auction database system in which members participate in the sale of items. The data requirements for this system are summarized as follows:

$$ The online site has members who are identified by a unique member id and are described by an email address, their name, a password, their home address, and a set of phone numbers.

$$ A member may be a buyer or a seller. A buyer has a shipping address recorded in the database. A seller has a bank account number and routing number recorded in the database.

$$ Items must be placed by a seller for sale and are identified by a unique item number. Items are also described by an item title, an item description, a starting bid price, bidding increment, the start date of the auction, and the end date of the auction.

$$ Items must be categorized based on a fixed classification hierarchy $($for example a modem may be classified as $/$COMPUTER$/$HARDWARE$/$MODEM$).$

$$ Buyers may make bids for items they are interested in$.$ A bidding price and time of bid placement is recorded. The buyer at the end of the auction with the highest bid price is declared the winner.

$$ Buyers and sellers may place feedback ratings on the purchase or sale of an item. The feedback contains a rating and a comment.