Access 2007
Creating a Database
Sheila Dixon & Diane Skinner – September 2010
Creating an Access Database
Changing the datatype
1.
Click on the Office button.
1.
2.
Choose New.
3.
Select Blank database.
Click anywhere in the field/column whose datatype
you want to change.
2. Locate the Data Type box on the Datasheet tab and
select an appropriate data type from the dropdown
list:
Text
Up to 255 alphabetic or numeric.
Memo
Maximum of 65,535 characters.
Useful for notes or comments.
(Cannot be sorted.)
Number
4. In the File name box type the name of the database
and if necessary change the drive and folder to
save the database in.
Any number – but beware if you will
ever need to add a letter e.g. 13A, or
add a space between e.g. 01482
464692 you must use a text field.
Date/Time
For years 100 to 9999.
5.
Currency
Adds a £ sign to the front of numbers
and two decimals to the end unless
specified differently.
Auto
Number
A meaningless number automatically
incremented when a new record is
added. Entries can’t be changed.
Yes/No
Can contain only Yes or No.
OLE Object
Object created by another program i.e.
drawing or scanned image.
Hyperlink
Can be a hypertext address
http://www.hull.ac.uk
or a file location i.e. c:\students\CV
(a file called CV in the students
folder).
Lookup
Wizard
Takes you through the steps required
to create a list of possible values that
you can choose from.
Click on Create.
Creating a Table
The first step in database creation is the table, as it is
this that the queries, reports etc are based on.
If necessary, click on the Create tab and then the Table
button. You can now simply start to enter data into the
table. Access 2007 will give each field a name and
assign a datatype, based on the data you enter.
Note that Access automatically inserts a field called ID
and makes it the Primary Key (see next page). This is
an autonumber type and data cannot be entered
directly into it.
Renaming a Field
1.
Click in the field (column) you wish to rename.
2. Click the Rename button on the Datasheet tab.
3. Type in the new field name and then press Enter.
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Different Table Views
Property Types
A table can be viewed in any one of 4 ways.
The properties available depend on the data type
selected.
Datasheet view is the default view and is used
mainly for entering and viewing data
Field Size The default is 255 for text, but can be
between 1 and 255. Changing this prevents too much
data being entered into a cell.
PivotTable view – used to create and view a Pivot
Table.
The default size for a numeric field is long integer,
which will only store whole numbers. To store decimal
numbers choose either Single or Double (see help for
more information).
PivotChart view – used to create and view a Pivot
Chart.
Design view – used to setup and change the structure
of the table.
Format Determines how the field contents are
displayed.
Switching between views
Numbers can be: general (as entered), currency, fixed
to a number of decimal positions, percentages or
scientific.
With the table open in Datasheet view, either
Click on the arrowhead on the word ‘View’ on the
View button on the Home ribbon and select the
required view.
Date/Time – choose from long, medium and short
date and time formats.
Or
Custom formats – you can create your own format if
the one you want isn’t available.
Click on one of the buttons found in the bottom right
corner of the window.
Decimal Places Choose between 0 and 15 decimal
places for number and currency data types.
Datasheet
PivotTable
PivotTable
Validating
Data
Design
PivotChart
PivotTable
PivotTable
It is important that the data entered is valid.
Input Mask Determines how data is entered. For
example an input mask of 00/00/0000 would ensure
that the full 4 digit year is entered.
PivotC
hart
Default values Cuts down the amount entered Could
be Hull for town name or =Date() to automatically
time stamp a field.
Properties
Each field has a number of properties that further
define the data that is stored in it.
Validation Rule Some validation takes place
automatically i.e. you cannot enter text into a numeric
field. Use if you want to ensure that the fee entered is
within certain limits, for instance less than £1000.
To view the properties, you must be in Design view.
Validation Text The message that will appear if the
rule above is broken.
Require Data Entry If it is important that a value is
added to each record, i.e. a student name, the required
property can be set to Yes. You cannot save a record
unless this field contains data.
Zero Length Strings A zero length string “” can be
used to differentiate between a field with no entry and
one for which you have no data (null entries) for
instance if a student doesn’t have a telephone you
could enter “” which will distinguish it from a missing
entry.
The bottom part of the screen contains the Properties
details of the selected field:
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Creating a Relationship between tables
Lookup Wizard
To further validate data you can use the lookup wizard
to limit data entry in a field to a typed list or the
contents of another table eg sex could be limited to
Male or Female or the Degree Titles from a table
containing details of the degrees on offer.
Once you have created the tables, you need to tell
Access how they are related.
Looking up Values from a Typed List
3. Select the related field from one of the tables and
drag to the related field in the other.
1.
2. Add the tables required and then click on Close.
In Table Design view:
1.
Click on the Relationships button on the Database
Tools ribbon.
Add a field name.
2. Select Lookup Wizard as the data type.
drag
3. Choose to type in the values. Click on Next.
4. Type the values in the column. Press the tab key to
move down a row.
5.
Referential Integrity
Change the column width if
necessary. Click on Next.
If you want to ensure
that there are no
instances of foreign
keys that do not
relate to a primary
key eg a tutor that
does not exist has not
been assigned to a module, check the Enforce
Referential Integrity box.
6. Add a name for the lookup
column.
7.
Click on Finish.
Limiting Entries to Lookup Values
In Table Design view:
1.
Click on the lookup tab in the field properties at
the bottom of the window.
Cascade Update/Delete records
2. At the bottom of the page, choose Yes from the
Limit to List option.
If a record is deleted or updated in one table you
can choose for the operation to be cascaded to
other related tables. To do this, check the Cascade
Update/ Delete boxes.
Limit to list
4. Click Create.
Primary keys
Creating a relationship using the Lookup
Wizard
When you create a new table, Access automatically
inserts a field named ID and makes this the primary
key field. You can change this if necessary. To add or
remove a primary key:
1.
If you want to limit the entries in a field to those in a
table e.g. degree titles could be stored in a table.
In Table Design view:
In Table Design view, click in the relevant field.
1.
2. Click on the Primary key button on the Design
ribbon.
2. Select Lookup Wizard as the data type.
3. Choose to lookup the values in a table or query.
Click on Next.
Creating a composite key
It is best practice that every table has a primary key
that uniquely identifies a record. There may be no
one field that would uniquely identify a record, but the
combination of two fields may resolve this.
1.
4. Select the table containing the values from the list
displayed. Click on Next.
5.
Drag over the field selectors
of the fields you wish to make
up the key.
Highlight the fields to be displayed in the list and
click on the arrowhead to add to the selected fields
box.
6. Click next.
7.
2. Click on the Primary key
button.
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Add a field name.
Change the column width if appropriate. Click on
Next.
8. Add a name for the lookup column. Click on
Finish.
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