Health Data Clinic - Book 3: Entity-Relationship Modeling

A database begins life as a drawing. Entity-Relationship modeling is how that drawing gets made, and this book teaches you to both read one and produce one. You start with entities, including the weak entities that cannot be identified on their own, then work through the four kinds of attribute and the keys that pick out a single row. Relationships come next in real depth: cardinality, participation, the degree of a relationship, recursive relationships where a table points back at itself, attributes that belong to the relationship rather than to either entity, and minimum and maximum cardinality written the standard way. A chapter on notation symbols means you can interpret any diagram put in front of you. The final chapters cover identifying relationships and where a foreign key should sit, the rules for turning a finished sketch into tables, and a validation pass that catches problems while they are still cheap to fix.

Twenty-six A4 pages, in full color. Written in short sentences and plain English, for readers whose first language is not English and clearer for everyone else because of it.

Every query in this book was run against a live database before the page was printed, so the result you read is the result you get. Instant PDF download. By M.R. Sterling