Database

State and explain the components of a database

A database is a structured collection of records or data on a particular topic that is stored in a system. Before computers address books, card indexes and telephone books were all types of databases. Computer databases enable the user to manage and manipulate the information that has been stored on the system. The computer database allows the user to input data from a variety of sources into the fields of a record and then access this data through reports and queries.. The records retrieved in answer to queries are information that can be used to make decisions

Computer database breaks down information into the smallest size. Each piece of information is input into a field. An example would be a name and address would not be listed in the normal way but would be entered into separate fields like first name, surname, address first line, Town County and country.

A complete set of fields relating to one topic is called a record. . All the records in the collection are stored on a table. The table can be viewed in datasheet view which is in columns for the fields and rows for the records or form view Ð'- this presentation is more like a paper form. The form view is often designed to aid the end user to input of information into each record in a friendly onscreen format. Tables can be sorted in a variety of ways including a-z, z-a, numerically, dated, etc A simple query of the above example could consist of all records with Kildare in the county field. This would return a list of the names and address of all people living in county Kildare.

Each record on a table can be assigned a primary key which is normally a number and is also a field in the record. This is a unique ID. This unique primary key allows records from different tables to be linked together in relational databases. This is were useful and is