Plzz don't laugh at my stupidity. I have no database designing experience. As part of an assignment, I have to design a databasefor a simple order entry application. I have to come up with an ER diagram & a schema drawings for each entity types showing attributes and relationships. I have pretty much done the ER diagram using Ms Visio. But I'm totally lost on the schema drawing. I don't know much about it and how to proceed. How is schema drawing different from an ER diagram? Can anyone shed some light.
An entity diagram is a conceptual data model showing the required entities, relationships and attributes - it is ana anlysis tool. A schema design shows an actual implementation in terms of tables and their foreign keys - it is a design tool. They often look very similar, but there are differences: for example, an entity diagram may show "many to many" relationships, but a schema diagram must show an extra table to implement that relationship.