BMGT 402 Lecture Notes - Lecture 2: Database Application, Query Language, Relational Model

• School: University of Maryland
• Department: Business and Management
• Course: BMGT 402
• Professor: Woei- Jyh Lee

Document Summary

Bmgt402 lecture 2 chapter 1: introduction continued, chapter 2: database environment, and chapter 3: database architectures beginning. Definition of data was embedded in application programs, rather than being stored separately and independently. No control over access and manipulation of data beyond that imposed by application programs: result: A description of this data is part of the database (aka metadata) Designed to meet information needs of an organization: system catalog (metadata) Enable program-data independence: logically related data comprises entities, attributes, and relationships of an organization"s information. Physically see/touch/use will be one entity put into a database. Will be outputted into a data model (chapter 4) relational model (chapter 12) entity-relationship model. Dbms (database management system: a software system that enables users to define, create, maintain, and control access to the database, database application program. A computer program that interacts with database by issuing an appropriate request (sql statement) to the dbms. Db approach: data definition language (ddl)