SESSION
5.1
In this session we will be exploring Pattern Match Queries
List-Of-Values Queries, Non-Matching Values in Queries
Both the “And” and the “OR” Operators Parameter
Queries (or “Prompt Queries”) CrossTab Queries
TopValue Queries
Microsoft Access 2000 Class #5
The Major Steps of a
MicroSoft Access Database
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Tables
Queries
Forms
Macros
Reports
Modules
On our road map, we are here!
Remember, a query is a
question you ask about
data stored in a
database.
Pattern Match Queries, List-Of-Values Queries,
Non-Matching Values in Queries, Both the “And”
and the “OR” Operators and Parameter Queries
(or “Prompt Queries”) are all simply normal select
queries that use criteria.
The Criteria Row
Last session we looked at defining record
selection by using criteria and creating
calculated fields in Select queries.
The Criteria Row
In this session we will look at specific
criteria in Select queries.
The Criteria Row
Let’s take a quick look at the “Like”,
“In”, “Not”, & the “And / Or”
comparison operators that we will be
using in our class exercise for this session.
The “Like” comparison operator (used in
pattern matches) selects records by matching
field values to a specific pattern that includes
one or more wildcard characters - asterisk (*),
question mark (?), and the number symbol (#).
To show only those records with an area code of
313 you would enter this in the Phone Criteria Row
In the previous example we used
parentheses ( ) in our criteria
expression.. If we had not needed
the parentheses we could have
simply typed 313* and Access
would have inserted the word
Like and the quotes for us.
The asterisk represents any string of
characters, the question mark represents
any single character, and the number
symbol represents any single digit.
Using a pattern match
is similar to using an
exact match, except
that a pattern match
includes wildcard
characters.
A list-of-values match selects records
whose value for the selected field
matches one of two or more simple
condition values. You could
accomplish this by including several
“Or” conditions in the design grid,
but Access also provides the “In”
comparison operator that works as a
shorthand.
The “In” comparison operator
allows you to define a condition with
two or more values.
If a record’s field value matches at
least one value from the list of values,
Access selects that record for
inclusion in the query results.
To show all records that contain
CustomerNum 123, 135 and 202 you would
enter this in the CustomerNum Criteria row
A non-matching value selects records
whose value for the selected field does
not match the simple condition value.
You create the selection criterion
using the “Not” logical operator.
To omit all states that begin with the letter M
you would enter this in the State Criteria row
You could also type just Not M* and Access
would insert the Like and Quotes for you.
Let’s talk about something called
compound conditions for a moment.
Barbara just came in and asked to see a
list of all customers in Ohio and
Michigan.
Notice the word “and” in Barbara’s
request.
What would happen if we typed “OH” And
“MI” in the State Field’s Criteria Row?
The result would look something like this, not
finding anything. That’s because we have asked
Access to show us all records that contain both
MI and OH in the same field.
To answer Barbara’s question we
would have to enter
This criteria would return something like
You have the option of entering this
criteria in two ways
Using the second method as shown below
Would return only records in Ohio that
contain “756” in the Phone field and every
record in Michigan.
Using the second method as shown below
Would return only records in Ohio that
contain “756” in the Phone field and only
records in Michigan that contain “756” in the
Phone field.
Hmm??
Lately it seems as though the questions are
getting more and more intense!
What if ?
Barbara especially is beginning to realize
that many unsolved mysteries can be solved
with this program by using queries.
This has been causing
Barbara’s Staff a
considerable amount
of concern.
Two things have been
happening. First, more and more
time has been spent creating
queries.
Secondly, The number
of queries is growing
and it’s becoming
more and more
difficult to keep
track of which
query is which.
There is an answer to this dilemma!
The wizards
at Microsoft
have come up
with a very
simple
solution!
The solution is a
parameter query!
A parameter
query is a
query that
prompts you
for criteria
when the query is viewed or run.
When Access runs the query, it will
display a dialog box and prompt
you to enter the criteria desired.
To create a parameter query, simply enter the text that you
want as your prompt in square brackets in the criteria row
for the field that you want to set the criteria for.
Leonard is interested
Can I. get in how much business
summaries
?
.
Valle Coffee is .
doing in each .
state! He wants .
to know the
.
total sales by .
state and by
.
month.
Is the Sun
in the Sky?
The answer is
“YES!”.
The solution is
“CrossTab
Queries”!
A Crosstab
query performs
aggregate (total)
function
calculations on
the values of one
database field,
and displays the results in a
spreadsheet like format.
The quickest
way to create a
crosstab query is
to use the
Crosstab Query
Wizard, which
guides you
through the steps for creating
crosstab queries.
A Crosstab
query can also
display one
additional
aggregate
function value
that summarizes
each row’s set of
values.
The crosstab query
datasheet below shows
the total sales for each
month by state and
shows a row total.
There are 3
other types
of select
queries that
we need to
take a quick
look at.
Find Duplicates
Find Unmatched
Top Values
Finding duplicate
records in very
large databases
can be a very
distasteful and
tedious task
A find duplicates
query is a select
query that locates
duplicate records
in a table or
query.
You can create this type of query using
the Find Duplicates Wizard!
Finding
unmatched
records in very
large databases
can also be a very
tedious task
A find unmatched
query is a select
query that locates
unmatched records
in a related table.
For example, if you can not establish
referential integrity between
the Customer Table
and Order Table,
you might have a
customer # in the order
table that does not exist in
the customer table.
You can create this type of query using the
Find Unmatched Query Wizard!
The last select query that we will
explore is called a
Top Values Query
Whenever you have a query that
displays a large group of records,
you can limit the number to a
more manageable size by
showing just the first 10 records
for example.
The Top Values property for a query
lets you limit the number of records
in the query results. For the Top
Values property, you enter either an
integer (such as 10, to show the first
10 records) or a percent (such as
50%, to show the first half.)
The Top Values Query Button can be
found on the Query Design Window’s
Tool Bar as shown below:
Quick Check Review
Page AC 5.23
Quick Check
Review
Let’s take a few
moments to break up
into discussion groups.
Each group will discuss
the quick check questions on page AC
5.23 in your books. We will then review
the answers at the end of the discussion.
Quick Check Review
Session 5.1
1) What is a Lookup Wizard field?
Quick Check Review
Session 5.1
2) What is a subdatasheet?
Quick Check Review
Session 5.1
3) A(n) ___________ is a
predefined format you use to enter
data in a field.
Quick Check Review
Session 5.1
4) Which comparison operator is
used to select records based on a
specific pattern?
Quick Check Review
Session 5.1
5) What is the purpose of the
asterisk (*) in a pattern match
query?
Quick Check Review
Session 5.1
6) When do you use the In
Comparison operator?
Quick Check Review
Session 5.1
7) How Do you negate a selection
criterion?
Quick Check Review
Session 5.1
8) When do you use a parameter
query?
Here we go
again !
The staff at Valle Coffee have just
finished their weekly meeting and
as you can expect, there are more
questions
than ever to
be answered!
Your task today is to complete the
exercises in Tutorial #5 Page AC
5.14 through Page AC 5.23
Please make a note that the disks
to use for today’s class are:
Tutorial #5
Level 2 Disk1