DATABASE Collection of centralized data Controls redundant data Data stored so as to appear to users in one location Services multiple application
HUANG Lihua, Fudan University DATABASE • Collection of centralized data • Controls redundant data • Data stored so as to appear to users in one location • Services multiple application
ADATABASE MANAGEMENT SYSTEM (数据库管理系统DBMS) Software to create maintain data enables business applications to extract data independent of specific computer programs
HUANG Lihua, Fudan University DATABASE MANAGEMENT SYSTEM (数据库管理系统DBMS) • Software to create & maintain DATA enables business applications to extract data independent of specific computer programs
■ Class programs Class file Accounts programs Class file accounting athletics Sports programs Class file Computer based files of this type cause problems such as redundancy, inconsistency, and data isolation. registrar em Class programs Database accounting Accounts programs DBMS Class file 删HH Accounts file Sports file Sports programs athletics m DBMS provides access to all data in the databa
HUANG Lihua, Fudan University registrar accounting athletics Class programs Class file Accounts programs Class file Class file Sports programs Computer based files of this type cause problems such as redundancy, inconsistency, and data isolation. registrar accounting athletics Class programs Accounts programs Sports programs DBMS Database Class file Accounts file Sports file DBMS provides access to all data in the database
Database environment INTEGRATED HUMAN RESOURCES DATABASE Employees Name Address Social security number Personnel Position application Personnel Marital status programs department Payroll Hours worked ate Database Payroll Gross pay management application system Payroll Fed tax programs department State tax Net pay Benefits Benefits Life insurance application Pension plan Benefits program Healthcare plan department Retirement benefit
HUANG Lihua, Fudan University Database Environment
COMPONENTS OF DBMS DATA DEFINITION LANGUAGE Defines data elements in database DATA MANIPULATION LANGUAGE Manipulates Data for Applications For Example: For extracting data from database, e. g SOL DATA DICTIONARY Formal Definitions of all variables in database Controls variety of database Contents
HUANG Lihua, Fudan University COMPONENTS OF DBMS: • DATA DEFINITION LANGUAGE: – Defines Data Elements in Database • DATA MANIPULATION LANGUAGE: – Manipulates Data for Applications – For Example: For extracting data from database, e.g. SQL • DATA DICTIONARY: – Formal Definitions of all Variables in Database; Controls Variety of Database Contents *