1. Review of Main Database Features
-- Relationship Editor
-- Query by Example Grid
-- And/Or Logic
-- Sort
-- Total Query
-- Sum, Average, Count, Max
-- Group By, Where
-- Expression Builder
-- Inner/Outer Joins

2. Relationship Editor
The relationship editor is used primarily when you are
planning the query, i.e., identifying the tables that
contain data that must be included in the query and the
bridge tables that connect the tables containing the data.

3. Relationship Editor
In this query, fields are drawn from the Brides and
Product tables. Here are two versions of the query,
the first wrongly formed because the bridge table that
connects the Brides and Product tables was not included,
the second properly formed because the bridge makes
it possible to know which product goes with which bride.

4. Query By Example Grid -- Post Tables -- Select Fields from Tables
-- Sort fields alphabetically or
numerically
-- Set criteria for selecting records
using AND or OR logic
-- AND operates horizontally, e.g.,
a record must be Condy AND
22517 to be selected or Blather
AND
-- OR operates vertically. All
persons named Jilbert will be
selected (regardless of their zip
code since there is no zip AND)
along with Condy and Blather.

5. Total Query: 1 -- Total Query opened with sigma: ∑
-- Adds to query by example grid a
TOTAL row that combines
values in a single field.
-- Values in the field can be combined
by adding them all up, SUM, by
calculating their average, AVG,
by counting up the number of
records, COUNT, or by identifying
the largest, MAX, or smallest, MIN
value.

6. Total Query: 2 -- The GROUP By and WHERE options in a
TOTAL query can be
used to aggregate
subsets of records,
e.g., just the Flower
and Food records.
-- GROUP BY creates a separate record for each value found in the GROUP
BY field, i.e., for Flowers and Food in the example. GROUP By can be used
with or without criteria. When there are no criteria, subtotals are reported for
all values in the field, i.e., the query would yield subtotals for Apparel, Venue,
Food, Flowers, and Musicians since those five values exist in that field.
-- WHERE is used only with criteria and only when there is more than one value
in the criteria rows. It selects all records that meet the criteria, but then
treats them as one big group with only one average or summed value.
Result
Result

7. Expression Builder: -- Expression Builder opens
with the magic wand icon.
It is like a piece of paper on
which formulas may be
written--but you don’t have
to write the values. You can
just point and click to post
them on the writing slate.
Expression builder is used
to carry out some operation
on two or more fields to
create a new calculated
value. Formulas are standard
math. Nothing special.
(Quantity x Price) x FindFee

8. Inner Versus Outer Joins:
The join type determines which records will be reported when a
query is run. When an INNER join connects two tables, records
are reported only if there are values (a primary key value and a
matched foreign key value) in both tables. When a LEFT
OUTER join connects the tables, all records in the primary table
(table on the 1side of the 1 to ∞ relationship) are reported. Only
matched records (records with a foreign key value) in the related
table (table on ∞ side) are reported. When a RIGHT Outer join
connects the tables, all records in the related table (∞ side) are
reported. Only matched records in the primary table are reported.
-- The join type is specified in this
menu. Note that the effects of
establishing each join type are
described. Option 1 is an INNER
join, option 2 a LEFT OUTER
and option 3 a RIGHT OUTER
join.

9. Joins and their results are shown below. Note
that every vendor is matched with a product
in the inner join. The left outer join reports all
vendors (including 2 with no product). The
right outer join reports all products (including
2 that have no associated vendor).
INNER JOIN LEFT OUTER JOIN RIGHT OUTER JOIN

10. Your Task: Match Database Features with the Business Problem
-- Calculate the amount of tax your firm owes the state in the current year.
-- Your dealership sells three different kinds of sports car. What is overall
average amount that has been spent by people who bought a sports car?
-- Send a thank you card to customers who, in the last month, spent $500
or more on shoes or $1000 or more on a dress at your store.
-- Identify all the suppliers listed in your supplier table from whom you have
never purchased a product. Delete them from the table.
-- Determine how many purchases were been paid for by Master Card,
American Express Card, Visa, or cash during December last year.
-- What percentage of your overall sales did you pay to the credit card
companies in fees last year.
-- Run a query to identify the people who are your best customers—i.e., those
from whom you have earned the most money. Flag them in the database
so staff will bend over backwards to take good care of them.