PHIL 100 Study Guide - Quiz Guide: Sql, Data Manipulation Language, Data Definition Language

• School: University of Maryland
• Department: Philosophy
• Course: PHIL 100
• Professor: danmoller

Document Summary

Database management systems (dbms) - software for creating, maintaining, and manipulating data (known as database software) Interfaces between applications and physical data files. Separates logical and physical views of data. Eliminates inconsistency (same attribute has different value) Enables organization to centrally manage data and data security. Relational dbms - represents data as two-dimensional tables called relations or files, each table contains data on entity and attributes. Rows (tuples) - records for different entities. Fields (columns) - represents attributes for entities. Primary key - field in table is used to uniquely identify a table. Foreign key - primary key used in second table as look-up field to identify records from original table. Data definition language (ddl) - specifies structure of database content, used to create tables and define characteristics of fields. Data dictionary - automated or manual file storing definitions of data elements and their characteristics. Data manipulation language - used to add, change, delete, retrieve data from database.