normalisation
TRANSCRIPT
BBBIT Prepare for Learn
Text about stuff
BBBITBBBIT
By the end of today’s lesson;• All of you will understand what 1st,
2nd and 3rd normal form are• Most of you will design a database
in 1NF, 2NF and 3NF• Some of you will convert a
database between 1NF, 2NF and 3NF
Learning Outcomes
BBBIT
Normalisation is when we ensure a database is working in its most efficient way. Its main purpose is to;• Organise the data efficiently• Eliminate redundant data• Ensure that only related data is
stored in a table.
Normalisation
BBBIT
The rules for 1NF are;• There are no columns with
repeated or similar data• Each data item is atomic• Each row is unique• Each field has a unique name
1st Normal Form
BBBIT
Which is NOT in 1NF?
1NF Example
BBBIT
The rules for 2NF are;• Non-key attributes must depend on
every part of the primary key• The table must already be in 1NF
2nd Normal Form
BBBIT
How can we change this 1NF database to 2NF?
2NF Example
BBBIT
The rules for 3NF are;• There are no non-key attributes
that depend on another non-key attribute
• The table must already be in 2NF
3rd Normal Form
BBBIT 3NF Example
BBBIT
On your whiteboards convert this database to 1NF.
Task 1
BBBIT
On your whiteboards convert this database to 2NF.
Once you have done this create a design for a database in 3NF for an online game database that stores player details, games they play and high scores (max 3 games).
Task 2