Pa rt 1: Par t Title
Microsoft Office Access 2003 Inside Out
Pa rt 1: Understanding Microsoft Access
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Microsoft Access as an RDBMS
A Microsoft Access desktop database (which uses the .mdb file extension) is a fully functional
RDBMS. It provides all the data definition, data manipulation, and data control features you
need to manage large volumes of data.
You can use an Access desktop database (.mdb) either as a stand-alone RDBMS on a single
workstation or in a shared client/server mode across a network. A desktop database can also
act as the data source for data displayed on Web pages on your company intranet. When you
build an application with an Access desktop database, Access is the RDBMS. You can also use
Access to build applications in a project file (which uses the .adp file extension) connected to
Microsoft SQL Server, and you can share the server data with other applications or with users
on the Web. When you create a Microsoft Access project file (.adp), SQL Server (or the
Microsoft SQL Server Desktop Engine—MSDE) is the RDBMS.
Data Definition and Storage
As you work with a document or a spreadsheet, you generally have complete freedom to
define the contents of the document or each cell in the spreadsheet. Within a given page in a
document, you might include paragraphs of text, a table, a chart, or multiple columns of data
displayed with multiple fonts. Within a given column on a spreadsheet, you might have text
data at the top to define a column header for printing or display, and you might have various
numeric formats within the same column, depending on the function of the row. You need
this flexibility because your word processing document must be able to convey your message
within the context of a printed page, and your spreadsheet must store the data you’re analyz-
ing as well as provide for calculation and presentation of the results.
This flexibility is great for solving relatively small, well-defined business problems. But a doc-
ument becomes unwieldy when it extends beyond a few dozen pages, and a spreadsheet
becomes difficult to manage when it contains more than a few hundred rows of information.
As the amount of data grows, you might also find that you exceed the data storage limits of
your word processing or spreadsheet program or of your computer system. If you design a
document or spreadsheet to be used by others, it’s difficult (if not impossible) to control how
they will use the data or enter new data. For example, on a spreadsheet, even though one cell
might need a date and another a currency value to make sense, a user might easily enter char-
acter data in error.
Some spreadsheet programs allow you to define a “database" area within a spreadsheet to
help you manage the information you need to produce the desired result. However, you are
still constrained by the basic storage limitations of the spreadsheet program, and you still
don’t have much control over what’s entered in the rows and columns of the database area.
Also, if you need to handle more than number and character data, you might find that your
spreadsheet program doesn’t understand such data types as pictures or sounds.
An R DBMS al l ow s you to defi n e th e kin d of data you have and how t he d ata sh oul d be stored .
You can also usually define rules that the RDBMS can use to ensure the integrity of your data.
In its simplest form, a validation rule might ensure that the user can’t accidentally store
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