Non-Procedural Language

In Non Procedural Language user outlines the desired information without giving a specific procedure or without telling the steps by step process for attaining the information. It only gives a single Query on one or more tables to get .The user tells what is to be retrieved from the database but does not tell how to accomplish it.

For Example: get the name and the contact number of the student with a Particular ID will have a single query on STUDENT table.

Relational Calculus is a Non Procedural Language .

Relational Calculus exists in two forms:

1. Tuple Relational Calculus (TRC): Tuple Relational Calculus is a non procedural query language , It is used for selecting the tuples that satisfy the given condition or predicate . The result of the relation can have one or more tuples (row).
2. Domain Relational Calculus (DRC): Domain Relational Calculus is a Non Procedural Query Language , the records are filtered based on the domains , DRC uses the list of attributes to be selected from relational based on the condition.

SQL has its own querying methods to interact with the database. But how do these queries work in the database? These queries work similarly to Relational Algebra that we study in mathematics. In the database, we have tables participating in relational Algebra.

Relational Database systems are expected to be equipped with a query language that assists users to query the database. Relational Query Language is used by the user to communicate with the database user requests for the information from the database. Relational algebra breaks the user requests and instructs the DBMS to execute the requests. It is the language by which the user communicates with the database. They are generally on a higher level than any other programming language. These relational query languages can be Procedural and Non-Procedural.

Types of Relational Query Language

There are two types of relational query language:

• Procedural Query Language
• Non-Procedural Language