Description of a database and it's features!

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Description of a database and it’s features!

A database can become very helpful for many people, especially if the person has their own business or responsibilities to look after a lot of information, that they require to look at every now and then.

By using a database, you can make it possible for yourself to search for various information quickly and easily.

A database has to consist of many relations, so that all the information in the database can link together and be searched for easily.

     Data is arranged into various tables  (preferably two or more), and as I have mentioned above, the data is linked together with the aid of relations.

With a database various searches and reports can be produced based on the needs of the user.

This is extremely flexible and can save space by avoiding duplication.

     Each table in a database is made up of fields and records.

Fields have different formats depending on the type of data they store.

Examples of various kinds of fields and their formats:-

Type of data- text, category- Basic - Mixed letters and/or numbers,

What is included in it- Up to 255 characters (letters and/or number codes).

Number: -Integer- Whole numbers between -32,768 and +32,767

-Long Integer- Whole numbers between -2,147,483,648 and +2,147,483,647

-Byte- Whole positive numbers between 0 and 255

 

-Single- Any number (accurate to 7 significant figures)

-Currency- Up to 15 figures before decimal place, 2 after - e.g. £1,234.56

-AutoNumber- Automatic counter - incremented by 1 for each record.

Special: Date/Time- Both date & time - e.g. 25/12/98 16:25:08

-Yes/No True/False On/Off - For data with only 2 possible values

  • OLE Object- For pictures, sound, video, Word/Excel documents etc.

-Hyperlink-  For links to the Internet or e-mail.

All of the information mentioned above is all about the different types of fields that can be used in databases.

All of these fields above are found within tables and various tables can be linked together by the power of relation database.

When tables are linked together they form a relationship.

A relationship enables tables to have some sort of a link with each  other, so when a search is entered into the database, all the information form various tables links up and provides the necessary information.

The best way of putting information into a table is by using a Form

When a Form is created it appears on the screen and prompts you for the information a field at a time

You can design how the Form will look or you can ask the computer to provide designs by using the Form Wizard

      Once you have designed the fields for each record in your table, this is how the computer is to be used to be able to find a particular record:-

To help the computer you have to choose a particular field as a Primary Key.

The field chosen as the Primary Key must contain unique data for each record in the table.

Examples:-

A field called Surname should not be used as a Primary Key because two people in the table might have the same surname!

A field called Date of Birth should not be used as a Primary Key because more than one person in the table might have the same Date!

Usually a Primary Key is a field, which, within its table, contains unique data for each record.

Some times there are a number of fields, which could be Primary Keys.

Some times it is necessary to create an extra field such as Reference Number if no other field in the table is likely to contain unique data!

To obtain information form a database, the best method to use it to:- produce a query.

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Now a query is used, usually if you want to search for a particular piece or group of information.

The easiest way to search for information on the Access database is by using a Simple Query Wizard The Query you create produces a new table which you can print out by producing a Report The easiest way of producing a report on the Access database is by using the Report Wizard 

Evaluation of my own database!

The database that I have produced is all about football.

It is based on the premier league teams, and it ...

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