Database Design video course and notes
Data is stored about entities.
Entities have attributes. The attributes are stored in database tables.
rows contain specific attributes for a given entity.
columns contain a list of the same attribute but for different entities eg usernames.
Entity type - Category of entity eg User, a specific entity would be paul.
Attibute type - Category of attribute eg username
(Relational) Database management system
DBMS allows data to be viewed and queried and manipulated.
Views can be created to allow access to different fields to the data.
examples of RDBMS include - MySQL - SQL server - ORACLE - PostgreSQL
Data for a database is stored on disk.
The database management system coordinates all the data moving in off disk and associating it with the correct table.
Structured Queried Language
All databases use a version of SQL.
SQL is used to define database structure, and then manipulate the data within.
DDL - data definition language
DML - data manipulation language