Database Keywords

Database Keywords

1. Data Redundancy

   • Data redundancy is where you have data that is no longer needed.

2. Foreign key

   • A Foreign key can be in a second table.

3. Primary key

   • There is only one primary key in a table so they are unique.

4. Entity

   • A entity is a real world object. For example a database table.

5. Boolean

   • Yes/No True/False 1/10

6. Relational Database vs Flat file database

   • A flat file database has data redundancy because it has no primary or foreign keys.
   • A relational database is structured to recognise relations between stored items of information.

7. Validation checks

   • Length ckeck
     • Checks how many characters are in a string. For example a phone number can only have 11 characters in it.
   • Presence check
     • Makes sure that the data exists and is complete.

8. DBMS

   • Database Management System.
   • Why is it good?!
     • Easier to maintain
     • Easier to keep secure
     • Safe from corrupt
     • Set up by experts + used by end user
     • Database can be accessed in multiple ways
   • Facebook DBMS
     • Tablets
     • Iphone app
     • Android app
     • Web browser
     • Windows app
   • Runs a report