Database Report

A relational database is a collection of data, each piece of data is known as a field. This fields are separated into tables made up of columns and rows. The columns in databases are called attributes and the rows are called tuples as shown below. An example of this could be a business order entry database which would have a table for customers containing columns with Name, Address, Contact Number etc. A further table would be used for orders including Product, Customer, Order Date, Price etc. With this information in place an employee can search or do a ‘query’ for particular information. For instance they could look up accounts to be paid using certain search criteria and the results would be returned filtered to contain only this data.

The language used to interface with relational databases is known as SQL (structured query language). Using this language the user can accumulate data for reports and use interactive queries for data from a relational database.

A database needs to be organised so that there is no repetitious or redundant data being stored in more than one table. This process is called normalization and consists of five stages called normal form (1NF), second normal form (2NF), third normal form (3NF) and so on. Fourth normal form is used occasionally and fifth normal form is very rarely used. Third normal form is the most common normalization used for practical applications. The end result eliminates any duplication of data and thus avoids any problems with the database. Normalization is only a guideline but is almost always followed.

The managing of databases is done by using software known as a database management systems (DBMS). After the process of normalization the tables and fields can be entered into a database using the software to create forms on which anyone can then enter data into the individual fields. The data can then be stored and retrieved using query forms as described in paragraph one. Reports can also be produced in the same way using certain search criteria. Another feature in the software is the use of Forms which is basically a simpler or user friendly entry form for entering data.