Characteristics of Data in Database

Characteristics of Data:

Computer uses database by adopting a set of well defined rules. You should note that just like a mailing is the below figure shows that the mailing box is filled with cards, so it is a computer database filled with records. And while each card in the box may contain several lines of written information. A record in a database contains several fields of data items. Thus, a mailing box contains cards, each of which has several lines of information on it.

Similarly, a database contains records, each of which in turn has fields in it. Assume that each in the mailing box has five lines of data items, namely,
i. Name;
ii. Locality;
iii. City;
iv. State;
v. Pin_code;

Then, all these fields are combined to form a record. We shall now understand each part of a database one by one.


The smallest piece of meaningful information in a file is called a data item or field. A data item is generally used for a group of alphanumeric characters. The above figure displays the data items (fields) in a record. NAME, LOCALITY, CITY, STATE, and PIN_CODE are all known as data items or fields.


The collection of related fields is called a record. For example, The above figure shows that it contains six records and each record has five related fields namely, NAME, LOCALITY, CITY, STATE, and PIN_CODE.


File is the collection of all related records. The above figure shows that the file contains the list of addresses of six friends.


Database is a collection of related files. The above figure shows that the Employees database has related files containing records of employees.

Key Field:

In above figure, File 1 contains employee records with fields Emp_Code and Address. File 2 contains employee records with fields Emp_code and Salary. File 3 contains employee records with fields Emp_code and Name. All three files have one common field called the keyfield. It is used for identifying and relating records. The key field in a record is a unique data item which is used to identify the record to access and manipulate the database.