access 2003 in pictures phần 8 doc

WORKING WITH QUERIES 153The query Design View window should appear: 4.. In the Show Table window, click Customers, then click the button... Drag the Customer ID field from the Custome

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Create queries

1 Start Access, and open the FoodStore1 database

2 In the Objects list, click Queries

3 Double-click Create query in Design view

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The query Design View window should appear:

4 In the Show Table window, click Customers, then click the

button

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5 Click the button

This adds the Customers table to the query The query window

should look like this:

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Add fields to query

1 Drag the Customer ID field from the Customers table to the first

column of the query design grid

Release the mouse button

The query design grid should look like this:

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2 Drag the First Name field and Last Name field to the design grid

the same way

The design grid should look like this:

The query is now set up to show the Customer ID, First Name, and Last Name of each customer in the Customers table

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Run the query

1 On the Toolbar, click the icon

The query window should now look like this:

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The query shows the Customer ID, First Name, and Last Name

of each customer in the Customers table:

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Sort results

1 On the Toolbar, click the icon to return to the query Design

View

2 In the Last Name field, click in the Sort row

When the drop-down arrow appears, click it, then click

Ascending

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It should look like this:

3 On the Toolbar, click the icon

The query should run, and sort the records alphabetically by

Last Name:

4 On the Toolbar, click the icon to return to the query Design

View

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5 In the Customer Last Name field, click in the Sort row, then

click (not sorted)

It should look like this:

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Add criteria

1 In the query’s Customer table, scroll down to the State field

2 Add the State field to the query design grid

3 In the State field, click in the Criteria row

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4 Type:

FL

5 Press the ENTER key

It should look like this:

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Tip: Notice that Access automatically surrounded the FL

criterion with double quotes That’s because the State field stores text data In database query language, double quotes signify a string of text

If this field held date data, Access would have surrounded it with hash marks (#)

If the field stored number data, Access wouldn’t have added anything

6 On the Toolbar, click the icon

The query results should look like this:

It has returned all customers who live in the State of FL

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Employ Boolean operators

What are Boolean operators?

Boolean operators are expressions such as AND, OR, NEITHER, and NOR that allow you to add multiple criteria to a query They take their name from George Boole, the mathematician who first used them

If you had a T-shirt store with an Access database, for instance, and you wanted to find out how many of your California customers had

ordered blue T-shirts, you’d employ the AND operator in your query:

customers from California

AND

who also bought blue T-shirts

If you wanted to see how many customers were from California (these California customers could have bought T-shirts of any color),

and how many customers bought blue T-shirts (these blue T-shirt

customers could be from anywhere),

you’d employ the OR operator:

customers from California

OR

customers who bought blue T-shirts

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Employ the OR operator

1 Click the icon to return to the query Design View

2 In the State field, click in the or row under the criterion “FL”

3 Type:

MD

then press the ENTER key

The design grid should look like this:

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Tip: The two common Boolean operators are AND and OR They’re easily confused If you don’t know which to use, ask yourself the purpose of the query:

Do I want to find customers with a state of both Florida AND Maryland?

No—a customer can’t be in two places at once

Do I want to find customers with a state of either Florida OR Maryland?

That makes sense, so this query would use the OR operator

4 Click the icon

The query results should look like this:

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Employ the AND operator

1 Click the icon

2 Remove the query criteria from the State field

(Highlight them, then press the DELETE key.)

The Criteria row in the design grid should be blank:

3 Add the Company Name field to the query:

Drag it from the field list in the Customers table and drop it in

the blank field to the right of the State field in the design grid

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4 In the Company Name field, click in the Criteria row

5 Type:

A*

then press the ENTER key

Tip: An asterisk (*) stands for any character or combination of characters For instance, Ap* would match Ape, Aptitude,

Apparent, etc

6 Click the icon

The query results should look like this:

The query shows all companies whose names begin with A

7 On the Menu Bar, click File, then Save

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8 When the Save As window appears, type:

Companies that begin with A

in the Query Name box

9 Click the button

10 On the Menu Bar, click File, then Close

You should return to the FoodStore1 database window

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Find duplicate records

1 Make sure Queries is selected in the Objects list

2 On the Toolbar, click the icon

3 When the New Query window appears, click Find Duplicates

Query Wizard

Then click the button

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4 When the next screen appears, click Table: Customers, then

click the button

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5 When the next screen appears, double-click First Name, then

Last Name to add the fields to the query:

Then click the button