 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

NameAddressTelephone No. Martha12 Main St. Walsenburg, CO John34 3 rd St. Walsenburg, CO

 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 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 CharacterDescription 0Digit (0 to 9, entry required, plus [+] and minus [–] signs not allowed). 9Digit 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). LLetter (A to Z, entry required). ?Letter (A to Z, entry optional). ALetter or digit (entry required). aLetter or digit (entry optional). &Any character or a space (entry required). CAny 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.