What is a Database?

“A persistent & organised store of data. ” Persistent:  Non-volatile  Using secondary storage Organised:  Data organised into tables, records & fields

Important Database Words Entity Table Record Field Relationship Primary Key Foreign Key Query

Tables, Records & Fields Movie TitleGenreYear Released Star Wars Sci Fi1977 Ice Age Animation2002 Wall E Animation2008 Avatar Nonsense2009 TABLERECORDFIELD

Database Examples  What databases do you know of?  What entities are involved in these example databases?

The Task DesignBuildingRelationshipsQueryingReports/Interface  Create a database that stores information about recent film releases.  The database will need to store information about the actors  You will be free to decide the type of information that needs to be stored about each film.  Film reviewers will also need to be able to submit reviews for each film

Step 1 - Design  Its important to design the database well.  To do this you use entity relationship diagrams (ERD’s)  Each table in the database is a separate entity Teachers name DoB address subject niNumber salary startedJob teacherNo Entity An entity is a real-world object, about which data is stored.

Data Types  Just like programming databases like to categorise the data  Some of the most used types are in the table  There can be a difference between different database systems Text Varchar() Text Number tinyInt() Int() bigInt() float Date dateTime() Timestamp() MySQL Data Types