How do i know which joining type to use?!

[ReallyConfused!]

I'm trying to create an orders/supplier/dispatcher/buyer database.

its telling me about joining types in the book im using as help, tho i dont
understand which type im meant to use as they dont really describe what
theyre for. There's three options...!

my tables basically go ---- CUSTOMER ---->EMPLOYER

l------->EVENT------->COURSE---->CATEGORY

l-------->SUPPLIER

l-------->INVOICE

l-------->ORGANISER

Does anyone understand what i have to do?!

Victoria

 

[Yanick]

There is in fact 3 type of join : Inner join, Left join & Right join.

- Inner join will show you records where the join of both table are equal.

- Left Join will show you all record from the first table and only those
from the second table where the join is equal.

- Right join will show you all record from the second table and only those
from the first table where the join is equal.

I stongly suggest you to play with queries and try different combinations on
join type. It will help you understand join type.

Yanick

 

[Ofer Cohen]

Check this links:
Introduction to Data Modeling:

http://www.databasedev.co.uk/data-modeling-database.html


Query Joins - Inner & Outer Joins - Database Solutions for Microsoft Access :

http://www.databasedev.co.uk/query_joins.html