E-R to Relational - Basic Strong entity Table with all attributes of that entity Relationships Table with primary keys of participating entities Weak entity Table with primary key of strong entity Multi-valued Attribute X Table with X, primary key of strong entity Row per value of X Finally ..

E-R to Relational - Improved For N-1/1-1 relationships Move relationship attributes to the N-side entity’s table Dept id moves to employee. No need for a table for the relationship relating a weak entity Remove the “depends” table

Emp-Dept ER Diagram department car dependent employee Dept id name Manages department city state color Lic# car Supervises Start date Works for dependent supervisee supervisor employee reln name Supports Owns SSN Name address phones street city

Emp-Dept schema Employee(SSN, name, street, city, deptid, startdate, supervisor_ssn) Dept(deptid, name, city, Manager-SSN) Phone(SSN, phone#) Dependent(EMP-SSN, Name, relation) Car(state, license#, color) CarOwners(owner-SSN, car-state, license#)