CIS 3530 Lecture Notes - Lecture 2: Data Manipulation Language, Data Dictionary, Multivalue

• School: University of Guelph
• Department: Computing and Information Science
• Course: CIS 3530
• Professor: Fangjyu Wang

Document Summary

The result of compiling / interpreting a ddl program is a set of tables, whose de nitions are stored in a data dictionary. Data dictionary - is a db component that contains metadata, that is data about data . When you write a query, the system will check the data dictionary to make sure the query is accurate. Manipulation - load, search, delete, update the data. Queries are embedded in application programs (ie in javascript code) Queries are stand alone (ie, query the db directly on command line) Procedural - the query speci es (to some extent) the strategy (procedure) used to nd the desired data. Declarative - (non-procedural) the query only speci es what data are wanted, not how to. Start with gathering data about the real world for the db you are creating, gure out what data you will need to be storing. (right side of gure - database design) *mostly learning this in this course.