Microsoft Microsoft Access 2000Access 2000

Database Database and Tablesand Tables

MELJUN CORTESMELJUN CORTES

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Setting up a Database

To get started with Access 2000, we first create a database:

1) Start Access 2000.

2) In the Microsoft Access dialog box, select Blank Database , then click OK .

3) In the File New Database window, decide where to store the database.

4) Click Create .

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Tables

� The first object to be added to a database is a table.

� The rows in the tables are called RECORDS.

� The columns in the tables are called FIELDS. A field contains specific piece of data with a record.

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Tables

� PRIMARY KEY (or Unique Identifier) is a field that uniquely identifies each record in the table.

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Creating Tables

� Create Table in Design View.

� Create Table by using Wizard

� Create Table be Entering Data

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Creating Tables

� In creating a table, we describe the STRUCTURE of the table by describing the fields.

� For each field, we indicate the following:� Field Name - unique name within the table� Data Type - indicates the type of data

which a field can contain� Description - detailed description of the

field

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Field Names

The rules for field names are:� Names should be unique within a table, e.g., the

same names cannot be used for two different fields in the same table.

� Names can be up to 64 characters in length.

� Names can contain letters, digits, spaces and most punctuation marks.

� Names cannot contain periods, exclamation point (!), or square brackets ([]).

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DATA TYPES

� Text

� Memo

� Number

� Date/Time

� Currency

Autonumber

Yes/No

OLE Object

Hyperlink

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TEXTUSE:

� Text or combinations of text and numbers, such as addresses. Also, numbers that do not require calculations.

SIZE:

� Up to 255 characters

EXAMPLES:

� Phone numbers, Postal codes.

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MEMOUSE:

� Lengthy text and numbers

SIZE:

� Up to 64,000 characters

EXAMPLES:

� Notes, Descriptions

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NUMBERUSE:

� Numeric data to be used for mathematical calculations, except calculations involving money.

SIZE:

� 1, 2, 4, or 8 bytes.

� 16 bytes for Replication ID (GUID) only.

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NUMBERFIELD SIZE:

� Byte, Integer, Long Integer, Single, Double, Replication ID

FORMAT:

� General Number, Currency, Fixed, Standard, Percent, Scientific

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DATE/TIMEUSE:

� Dates and times.

SIZE:

� 8 bytes.

FORMAT:

� General Date, Long Date, Medium Date, Short Date

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CURRENCYUSE:

� Currency values.

� Use the Currency data type to prevent rounding off during calculations.

� Accurate to 15 digits to the left of the decimal point and 4 digits to the right.

SIZE:

� 8 bytes

FORMAT:

� General Number, Fixed, Standard, Percent, Scientific

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AUTONUMBERUSE:

� Unique sequential (incrementing by 1) or random numbers automatically inserted when a record is added.

SIZE:

� 4 bytes.

� 16 bytes for Replication ID (GUID) only.

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AUTONUMBERFIELD SIZE:

� Long Integer, Replication ID.

NEW NUMBER:

� Increment by One

� Random Number

� Replication ID (also referred to as GUID - globally unique identifier)

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YES/NOUSE:

� Fields that will contain only one of two values.

SIZE:

� 1 bit

FORMAT:

� Yes/No, True/False, On/Off

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OLE OBJECTUSE:

� Objects created in other programs using the OLE protocol, that can be linked to or embedded in a Microsoft Access table.

SIZE:

� Up to 1 GB (limited by disk space)

EXAMPLES:

� MS Word documents, MS Excel spreadsheets, pictures, sounds

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HYPERLINKUSE:

� Field that will store hyperlinks. A hyperlink can be a UNC path or a URL.

SIZE:

� Up to 64,000 characters

EXAMPLES:

� www.geocities.com/valdomero214.html