Post on 17-Jul-2015
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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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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