Document

Microsoft Office Access 2003
Tutorial 2 – Creating And Maintaining
A Database
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Learn the guidelines for
designing databases
XP
• When designing a database, first try to
think of all the fields of data that needs to
be stored.
• Next, group the fields into tables. Each
table will contain a group of related fields.
• You need to select a field in each table to
become the primary key for that table.
• When tables will be related to one another,
you need to include a common field in the
two tables that will be used to form the
relationship.
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Determining database fields
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Group the fields into tables
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Choose a primary key
• Choose a field or fields to serve as the
primary key for the table.
• A primary key must uniquely identify each
record in the table.
• Primary keys can consist of more than one
field.
• Primary keys with more than one field are called
composite keys
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Include a common field
• When one table needs to be related to
another table, you must include a common
field.
• The common field will be the primary key
in one table.
• The common field is referred to as a
foreign key in the related table.
• The foreign key in a table can then be used
as a primary key to access the record in
the related table.
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Data redundancy wastes
space and can lead to data
errors
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Setting field properties
• When assigning a name to any object in Access,
carefully select a name that will indicate what data
is stored there.
• Field properties include their data type, field sizes,
and an optional description of the field.
• When selecting a field size, make sure the size is
big enough to hold the largest piece of data that
will be stored there.
• Do not make the field larger then necessary because
this will result in wasted disk space
• Make sure the data type you select for a field is
appropriate for the kind of data to be stored in that
field.
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Access field types, slide 1
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Access field types, slide 2
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Create a new database
• You can create a new database by using a
Database Wizard or by creating a new,
blank database.
• When you create a new database, you will
need to create all the tables, queries,
forms, and reports for the database.
• This is the most flexible approach, since you will
create all objects yourself
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Create a database without
using the Database Wizard
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• To create a new, blank database without
using the Database Wizard:
• Start Access
• Click Blank Database in the task pane
• In the dialog box, navigate to the location where
you will save your database
• Enter the name of the database in the File name
text box
• Click the Create button
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Create a new table
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Define fields, and specify
a table's primary key
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• When you create a table, you name the fields and
define the properties for the fields.
• The table structure is set up and modified in Design
View
• In Design View, you will define each field that will be
included in the table
• When all the fields have been defined, you will then
specify which field(s) will be the primary key.
• The primary key is not mandatory, but it is a good idea
to assign one
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The database Design View
window
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Choosing a primary key
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Click a row selector for the field you want
to use as the primary key, and then click the
Primary Key button on the toolbar.
After clicking the Primary Key
button, a key symbol appears in the
row selector to indicate the key field.
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Save the new table
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• When all fields have been defined and
properties have been set, you must save
the table structure:
• Click the Save button on the Table Design
toolbar
• Type the name you want to assign to the table
into the Table Name text box of the Save As
dialog box
• Click the OK button to save the table using the
specified name
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Add records to a table
using Datasheet View
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• Once the table has been created, you can then add
records to the table using Datasheet View.
• As you enter records, they will be placed in the order in
which you enter them. However, when you close the table
and open it again, the records will be ordered according
to the primary key order.
• The navigation bar at the bottom of the Datasheet view
will indicate how many records are in the table and what
the current record is (i.e., the record on which your
cursor currently rests).
• You can move through the fields in the table by pressing
the Tab key.
• Once your cursor is moved off a record, that record is
automatically saved on your disk.
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Datasheet View with 2
records added
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Modify the structure of a
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table by deleting, moving, and
adding fields
• The structure of a table can be modified after it has
been created.
• To delete a field, enter Design View, right-click on
the field, and then click Delete Rows on the drop
down menu.
• To move a field, (you also do this in Design View)
click on the field you want to move, and while
holding your mouse button down, move the field to
the desired location.
• To add a field in Design View, right-click the field
where you want to insert the new field and then
click Insert Rows on the dropdown menu.
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Moving a field in Design View
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Adding a new field in Design
View
1. Right-click the row selector for the
field you want to insert the new field
in front of--StartDate in this figure.
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2. Select Insert Rows from the
shortcut menu, and a new, blank
row will be inserted before the
row you selected, as shown below.
3. Enter the
information for
the new field.
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Change field properties
• You can make additional modifications to the
structure of a table by changing the properties of
the table's fields.
• For example, if you have a field that represents a
currency value but you do not want to display dollar
signs, you could change the format to a standard
format
• In the Design View, you will find a list of all formats
available to you. You can make a selection from the
list of options
• Each data type has a separate set of options available
in the Field Properties portion of the Table Design
Window
• Field properties are changed in the Design View
window.
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Changing field properties
in Design View
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Copy records from another
Access database
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• If the data you want in your database already exists
in another Access database, you can copy the
records from that database into your database.
• You can use cut and paste to do this:
• Open the database that contains the records you want
to copy
• Select the records you want to copy and then press
the Copy button. This places the records onto the
Windows clipboard
• Open the database to which you want to copy the
records and open the desired table to receive the
copied records
• Place your cursor on the next available row in the
table and press the Paste button
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Import a table from
another Access database
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• You can also import an entire table,
including its structure, into another
database.
• To import a database table:
• Click the File menu
• Point to Get External Data, and then Import
• Locate and select the database and the table
you want to import
• This differs from the cut and paste method
because you actually import the entire
table, its structure, and its data.
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The Import Objects dialog box
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Copy and import
considerations
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• If you choose to copy records from one
table to another, it is very important that
you first determine that the two tables
have the exact same data structure.
• If the two data structures differ in any way, the
copy will cause an error
• When you import, you are importing an
entire table, including its data and its
structure.
• This is a good way to include a table in your
database that was previously designed in a
different database
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Delete and change records
• Once records have been added to a table, they can
be deleted or modified:
• In Datasheet view, click the row selector for the record(s)
you want to delete and then click the Delete Record button
on the toolbar
• To change or modify a record:
• Place your cursor on the record and then on the field you
want to change
• You can then edit the field's value as you wish by typing in
new data
• You can switch from navigation mode to editing
mode depending on what you want to do at the
time.
• When you are editing a record, you are in editing mode,
Otherwise you are in navigation mode
• Editing mode is indicated by a pencil symbol in the left
margin of the datasheet view
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An alternate method
for deleting a record
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Keystroke techniques for
navigation and editing modes
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Microsoft Office Access 2003
End
Tutorial 2 – Creating And Maintaining
A Database
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