Monday - Joins

Intro

Slides on Joins

###Basic Example

• Join main table to species table
• Show species and scientific name side by side
• Show distinct
• Filter by weight > 100 g

###What joins actually do

• Join species and plots tables

###Joins are part of the Query, not the database

• Save query
• Close query
• Open new query - shows no joins

###In Access they can be permanent - Relationships

• Save relationships
• Open new query - show joins
• Show that you can remove joins

Wednesday - Database Structure

Database Structure slides

Friday - Nested queries

Demonstrate by doing a query to get the number of trapping periods in each year.

• First GROUP BY yr and COUNT period
• Then GROUP BY yr and period
• Save that query
• Nest it to count the unique periods