A database is a collection of data that is organized so that its contents can easily be accessed, managed, and updated.

What is Database?

EXAMPLES OF DATABASES

ACCESS is a relational database management system.

Relational databases allow you to organize your data into tables

Each table focuses on a specific topic; the various tables can then be linked to each other for inquiry and reporting purposes.

What is Access?

Database Objects

Microsoft Access uses four objects to create a Database:

Tables Queries Forms Reports

Database Objects

A table is the basic element of a Database and contains the data entered by users.

Each row (or record) contains information about a particular item (e.g., an employee).

The record is made up of several fields; each field contains one piece of information relating to the item (e.g., employee's name, address, phone, etc.).

Table

Name Address Telephone No.

Martha 12 Main St. Walsenburg, CO

907-3621-2121

John 34 3rd St. Walsenburg, CO

977-3681-6121

A query extracts selected data from a table (or another query) and presents it in spreadsheet format.

Query

A form is a graphical template based on a table (or query).

It is used to enter new data into the database or display existing data.

Form

A report extracts selected data from a table (or query) and formats it for printing.

Report

A table is a database object used to store, organize and view data. All other objects are based on the data stored in tables.

Tables are comprised of:

Fields - represented by columns Records - stored as rows.

What is a Table?

Data Types

Any character (alpha, special characters, numbers)

Up to 255 in length

Numbers cannot be used for calculations

Text

Any character (alpha, special characters, numbers) Up to 65,000 in length

Numbers cannot be used for calculations

Field cannot be sorted or indexed

Memo

Numeric data to be used for mathematical calculations Not to be used for currency fields

Field Size property further defines its function and size

Number

Must be a valid date/time entry at entry time Format property determines display format

Date/ time

Accepts monetary values with a dollar sign and decimal point.

It can be used for computations

Currency

Creates a field that lets you look up a value from another table or from a list of values.

Lookup

Stores graphics, sound and other types of files attachments.

Attachment

Stores a value that contains a hyperlink.

Clicking the value activates the link and opens a webpage or addresses a message to an email address.

Hyperlinks

Stores Yes/No, True/False or On/Off Values

Yes/No

Adds a unique numeric field value to each record in a table.

Auto Number

Opens the Expression builder dialog box which lets you specify fields and operators to use in calculations.

Calculated

Field Properties

Sets a maximum size for data

Varies according to Data Type:

Field Size

Controls the way data is entered; frequently used for telephone numbers, postal codes, SSN #’s, date/time fields.

ACCESS offers a Wizard for text and date/time data types.

Input Mask

You specify text for the label attached to a field;

Will be used as the column heading when displaying tables, queries and reports.

The default value is Field Name.

Caption

Specifies a value that will be automatically entered when you create a new record.

Default Value

Input Mask Characters

Character Description

0 Digit (0 to 9, entry required, plus [+] and minus [–] signs not allowed).

9 Digit or space (entry not required, plus and minus signs not allowed).

# Digit or space (entry not required; spaces are displayed as blanks while in Edit mode, but blanks are removed when data is saved; plus and minus signs allowed).

L Letter (A to Z, entry required).

? Letter (A to Z, entry optional).

A Letter or digit (entry required).

a Letter or digit (entry optional).

& Any character or a space (entry required).

C Any character or a space (entry optional).

Primary Key

The primary key of a relational table uniquely identifies each record in the table.

It can either be a normal attribute that is guaranteed to be unique (such as Social Security Number in a table with no more than one record per person.