Question

What RAD?

What is a relational database?

What are the other types of DBMS?

What is a composite key?

What is a primary key?

What is a surrogate key?

What is a foreign key?

Answer 1

RAD

It is Rapid application development,

It is iterative software which uses case tools, prototypes and maintains a malleable management to develop an application system.

RAD model can be used only there is in need of high designers for the modelling section.

Relation Database

Relational database is a type of storing the data.

By dividing the data into its component parts for effective communication and connecting together with a relation.

Usage of Relation databases:’

1. Shops
2. Railways
3. Online shopping giants

Example: SQL

Types of DBMS

• Relational Database Management Systems
• Hierarchical Database Management Systems
• Network Database Management Systems
• Object-oriented Database Management Systems

Composite key

It is the combination of columns to identify each record in the table.

When two or more columns joined together then the composite key can create uniqueness among them.

Primary key

It is used to identify each record (row) in the table separately.

It is a unique key used for identifying each record separately.

For example:

People having their own aadhar number in India

People having unique finger prints in the world

Foreign key

It is a key in a table, which uniquely identifies the records (rows) in a table.

It links two tables together

It creates cross reference

It refers to the primary or unique key in another table

Surrogate key

A column or set of columns that are declared as the primary key instead of saying it as a natural key is called as a surrogate key.

It can be an artificial key.