EECS 1520 Chapter Notes - Chapter 12: Database Engine, Database, Database Model

• School: York University
• Department: Electrical Engineering and Computer Science
• Course: EECS 1520
• Professor: lew

Document Summary

Relational model: a database model in which data & the relationships among them are in a table. Query: a request to retrieve data from a data base. Key: one or more fields of a database record the uniquely identifies other records on tables. Field (attribute): a single value in a database record (select (take rows from tuples), project (takes columns from relations), join (both tuples. & relations) (select (attribute list) from (table list) where (condition) Structured query language (sql): a comprehensive database language for managing relational databases. Entity-relationship (er) modeling: a population technique for designing relational databases. Er diagram: chief tool used for er modeling that captures the important record types, attributes and relationships in graphical form. Cardinality constraint number of relationships that may exist at one time among entities in.