Database Key terms

Database Key terms

1. Table

   • Where data is stored

2. Field

   • Col in a table - 1 piece of information e.g title

3. Record

   • Row in a table- information about 1 person or things e.g criminal record

4. Primary Key

   • Used to uniquely identify data in a table. e.g exam number

5. Composite Key

   • like a primary like key - used to uniquely identify information
     • it uses 2 or more fields

6. Foreign Key

   • when the primary key appears in another table

7. Relational Database

   • Tables connected together with primary and foreign keys

8. Flat file database

   • Single tables not connected

9. Query

   • A search to find information in the database

10. Data types

    • The data item defined by the value it can take e.g Date and time /Text / Autonumber

11. Validation Rules

    • Check the data entered is VALID and REASONABLE
      • School students have to be aged between 11 and 16

12. ERD

    • Entity Relationship diagram
      • relationship between tables
        • 1 to many
        • Many to many
        • 1 to 1

13. Field Length

    • Number of Char allowed to be entered in a field
      • Firstname = 30 chars

14. Input Mask

    • controls entry in a field
      • Postcode _ LL9 9LL

15. Data Dictionary

    • Plan of a database table , details of structure - field length, validation rules

16. Normalisation

    • Reducing data that is not required
    • Separating data into tables

17. Database

    • Storing of data in a logical way