Download Data Storage & Retrieval: Access vs. Excel

Data Storage & Retrieval:
Access instead of Excel
MELISSA PICO
SUMMER 08
Two Peas in a…
Microsoft package
 Both Access and Excel…
 run queries to sort and filter data
 Run calculations
 Generate reports
 Use forms to navigate your data
 Have similar aesthetic components
Access vs. Excel
 In Access you can create multiple relational
tables, whereas, in Excel, you can only have nonrelational or flat worksheets-- they don’t interact
with one another
 In Access you can store more data than in Excel
(many thousands of entries, versus 15,000 rows)
 Access is better for long text “string type” data,
whereas Excel is better when working mainly with
numeric data and running statistical comparisons
with that data
Relational
Databases
Access allows the user
to create relationships
between similar fields
across different tables
or queries
Ex: If your study is
collecting demographic
info, and pre and post test
data for the same subjects,
creating a relationship
between the subject and
their responses, enable the
demographic data to be
linked to your subject’s
responses without having
to enter the data multiple
times
Relationships: Integrity is the key
 Access databases are all designed to enforce the
concept of referential integrity, which ensures that
relationships between tables remain consistent.
 TableA & TableB 



We may not add a record to the TableA unless it points to a
valid record in TableB.
If the primary key for a record in the TableB table changes, all
corresponding records in the TableA must be modified using a
cascading update.
If a record in the TableB is deleted, all corresponding records
in the TableA must be deleted using a cascading delete.
Monogamy isn’t for everybody
One-to-one relationships :
1 record in TableA corresponds to
1 record in TableB.
One-to-many relationships : each
record in TableA may have many
linked records in TableB, but each
record in TableB may have only 1
corresponding record in TableA.
Many-to-many relationships :
each record in TableA may
have many linked records in
TableB and vice-versa.
Storing Data
A unique attribute of
Access is that it stores
your data (in the form of
tables) inside Access itself.
This allows the user to
interact with a more
friendly layout called
“form view” without losing
the datasheets (tables) in
the background.
In form view, the user can
perform all the same tasks
as in the datasheet view
(change, delete, or add to
a record), but it is
presented in a more
aesthetically pleasing way
Retrieving
Data
Unlike Excel, with a
relational database you
can also use a query to
search multiple tables at
once!
Or, you can use a query to
merge the data of two
tables to create a new
table
Note: you can define the
specific “criteria” you are
looking for in a query! For
criteria examples, search
“criteria” in the help
menu, located in the
upper right hand corner,
identified by a question
mark 
Retrieving
Data
You can also retrieve data
using a form with
parameters.
To do this, first create a
query, and in the criteria
field, enter the text you
want the dialog pop-up
box to say, with brackets
at the each end. For
example:
[what cartoon?]
Then, create a form (using
form design), and define
the “record source” as the
query you created, the
dialog box will pop-up
when you open the form
Starting your Access database
 A Bottom-up process
 Think about what you will need you database to do with the
data you have
 will you need to be able to sort by date? query persons by age?
enter many records for one person? or one record per person?
 these questions are essential to define prior to starting in
access!
 Develop a list of questions you will want
your database to be able to answer.
Access 2007 Resources
 http://office.microsoft.com  help and how-to 
Access 2007 help
 UW library online (search through the uw catalog):
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Access 2007 for starters: the missing manual
Access 2007: the missing manual