Download Build a database IV: Create queries for a new Access database

ICT Staff Development presents:
®
Microsoft Office
®
Access 2007 Training
Build a database IV:
Create queries for a new
Access database
Course contents
• Overview: Ask your data — create queries
• Lesson: Get answers from your data
Each lesson includes a list of suggested tasks and a set of
test questions.
Build a database IV: Create queries for
a new Access database
Overview: Ask your data — create queries
It’s time to create queries, one of the
most powerful tools in your database.
Say you want to know how many
computers you own. You can build a
query to fetch that data and total the
numbers. Queries can also provide
data for your forms and reports, which
can help make your database easier to
build and use.
This course introduces queries and
explains how to create the most
common type, a select query.
Build a database IV: Create queries for
a new Access database
Course goals
• Use the Query Designer to create a select query that
returns data from a single table.
• Create a select query that asks you to enter parameters,
then returns results that match those parameters.
• Use a formula in a query to calculate a sum.
• Use the Query Wizard to create a select query that returns
data from two tables.
• Use a text expression to concatenate fields.
Build a database IV: Create queries for
a new Access database
Lesson
Get answers from your data
Get answers from your data
Your new assettracking database is
coming along.
You have tables,
relationships, and
data, so the next step
is to build some
queries.
Specifically, you’ll create select queries. They’re
components that retrieve and process your data and
display the results in a datasheet.
The query in the picture takes asset data from the first
table, the names of technicians from the second table,
and displays the result in a way that you can consume.
Build a database IV: Create queries for
a new Access database
The basics of creating select queries
Access provides two
primary ways to create
select queries — the
Query Wizard and the
Query Designer.
Regardless of the tool
you use, you follow
some common steps
to create the query.
1
Start by choosing a recordsource for the query. A
recordsource can be one or more tables, one or more
queries, or a combination of the two.
2
From the recordsource, select the fields that you want to
see in the query.
Build a database IV: Create queries for
a new Access database
The basics of creating select queries
Access provides two
primary ways to create
select queries — the
Query Wizard and the
Query Designer.
Regardless of the tool
you use, you follow
some common steps
to create the query.
3
Add any sorting, filtering, or other selection criteria to
your queries. For example, if you use the criteria shown
in the picture, the query will only return data for assets
purchased after May First of 2010.
4
After you finish adding fields and any selection criteria,
run your query to see if it gives you the correct results.
Build a database IV: Create queries for
a new Access database
Ways to use query results
When you run a select
query, Access displays
the results in a
datasheet.
The result is called a recordset, and you can work with
it in the same way that you work with a datasheet.
For example, you can add or change data, and Access
will write your changes to the tables that serve as the
recordsources for your query.
Build a database IV: Create queries for
a new Access database
Ways to use query results
You can also use your
recordsets to provide
data for forms, reports,
and even other
queries.
For example, if you want a report on the computers that
you need to replace, you can create a query that returns
that data, and then quickly build your report.
The picture shows this. The query returns only those
records where an asset has been marked for retirement.
Build a database IV: Create queries for
a new Access database
Query a single recordsource
The Query Designer
gives you the most
control over a select
query.
It also makes it easy to create a query that uses a single
table as a recordsource.
Build a database IV: Create queries for
a new Access database
Query a single recordsource
For example, this type
of query makes it easy
to list your assets and
their purchase dates,
as shown here.
1
On the Create tab, in the Other group, click Query
Design. The designer starts and displays the Show
Table dialog box.
2
In the dialog box, select your recordsource. You can use
a combination of tables and queries, and the ones you
select appear in the upper section of the designer.
Build a database IV: Create queries for
a new Access database
Query a single recordsource
For example, this type
of query makes it easy
to list your assets and
their purchase dates,
as shown here.
3
In your recordsource, double-click the fields that you
want to see in your recordset, or results. Your choices
appear in the bottom section of the designer.
4
When you finish adding fields, go to the Design tab on
the Ribbon, and in the Results group, click Run. Your
record then appears as a datasheet.
Build a database IV: Create queries for
a new Access database
Make a query ask you for input
The type of query that
you created in the
previous section can
return a lot of data. A
common way to limit
what the query returns
is to use a parameter.
Put simply, parameters make the query ask for input
before it runs.
So if, say, you only want to see records between certain
dates, you can add parameters that make the query ask
you for starting and ending dates. The query will give
you just the records that fall between those dates.
Build a database IV: Create queries for
a new Access database
Make a query ask you for input
In other words,
parameters are a type
of filter that you build
in to your query.
1
Open the query in Design view, and in the Criteria row
of the field you want to filter, enter your parameter.
2
When you run the query, that criteria asks you for a start
date, then an end date, and it returns only the records
that fall within the dates you specify.
Build a database IV: Create queries for
a new Access database
Use a formula in a query
Another common way
to alter the selection
criteria in a query is to
add a function.
For example, if you want to know how much your
company spent on office furniture last year, you can add
an aggregate function to the query and the sum will
appear in your results.
Build a database IV: Create queries for
a new Access database
Use a formula in a query
The picture shows the
process.
1
Open your query in Design view.
2
On the Design tab, in the Show/Hide group, click
Totals. The Total row appears in the designer.
3
In the field where you want to use the function, click the
Total row and select a function from the list.
Build a database IV: Create queries for
a new Access database
Use a formula in a query
The picture shows the
process.
4
When you run your query, the results include your
calculation.
Build a database IV: Create queries for
a new Access database
Query multiple recordsources
Finally, you can use
multiple tables, or
other queries, as the
recordsource for a
new query.
The Query Wizard is the easiest way to do that type of
job, especially if you’re new to Access.
This type of query is a way to answer questions such as
which assets came from which suppliers.
Build a database IV: Create queries for
a new Access database
Query multiple recordsources
The picture shows the
process.
1
On the Create tab, in the Other group, click Query
Wizard.
2
Complete the wizard. As part of that process, select the
tables and fields you want to use as your recordsource,
and ...
Build a database IV: Create queries for
a new Access database
Query multiple recordsources
The picture shows the
process.
3
Give your new query a descriptive name. Remember to
avoid using spaces in the name.
Build a database IV: Create queries for
a new Access database
Suggestions for practice
1. Create a select query from a single table.
2. Make the query ask you for input (add a parameter to the query).
3. Add a calculated field to the query.
4. Create a query from multiple tables.
Online practice (requires Access 2007)
Build a database IV: Create queries for
a new Access database
Test question 1
When you first create a query, you select which of the
following? (Pick one answer.)
1. A recordsource.
2. A system table.
3. A recordset.
Build a database IV: Create queries for
a new Access database
Test question 1: Answer
A recordsource.
The recordsource can be a combination of tables and queries.
Build a database IV: Create queries for
a new Access database
Test question 2
Use criteria in a query when you need to do which of the
following? (Pick one answer.)
1. Ensure your data is properly formatted.
2. Add formulas to a table.
3. Sort, filter, or otherwise limit what the query returns.
Build a database IV: Create queries for
a new Access database
Test question 2: Answer
Sort, filter, or otherwise limit what the query returns.
Criteria can be quite powerful, too. For example, you can use criteria to
find records for people who live in a given city and have birthdays that
fall between dates that you specify.
Build a database IV: Create queries for
a new Access database
Test question 3
Before you can use multiple tables as a recordsource, those
tables must be or do which of the following? (Pick one
answer.)
1. Be open in Datasheet view.
2. Participate in a relationship.
3. Not serve as the recordsource for another query.
Build a database IV: Create queries for
a new Access database
Test question 3: Answer
Participate in a relationship.
If the tables don’t participate in a relationship, the query returns all the
data in each table, and the results are almost always meaningless.
Build a database IV: Create queries for
a new Access database
Quick Reference Card
For a summary of the tasks covered in this course, view the
Quick Reference Card.
Build a database IV: Create queries for
a new Access database