Object Role Modeling (ORM) is a powerful method for designing and querying database models at the conceptual level, where the application is described in non-technical terms.

1. Object Role Modeling Prepared by Ahmed Magdy Ezzeldin

6. ORM Process To model any application using ORM we need to follow these steps starting from the requirements provided by the domain expert: 1. Transform information examples into facts 2. Draw the Entity & value types 3. Add Fact types and assign roles 4. Add constraints

7. ORM Symbol Glossary Value Entity Description Symbol Example Entity Type Student, course, song, band Value Type Student name, course name, song title, band name Fact with 2 roles (Predicate with 2 arities) Student is enrolled in course Uniqueness Constraint (has one) the first role is unique ti the second role. Each student has at most 1 name but there may be 2 students who have the same name 1:1 both roles are unique to each other Every student has at most one name and there are no 2 students with the same name. m:n Many to many Every student may be enrolled in many courses and each course may have many students.

9. Questions Thank you Questions ???