What is SQL?

SQL is a standard language to manage the Relational Database Management system (RDBMS)

SQL stands for …
Structured Query language (Or)

Standard Query Language

History of SQL:-

SQL is called as different names like SQUARE, SEQUEL, SQL and T-SQL

SQUARE - Specifying QUeries As Relational Expressions

SEQUEL - A Structured English Query Language

SQL - Structured Query language

T-SQL – Transact SQL

Elements of SQL language:

The SQL language is subdivided into several language elements, including: Clauses, Expressions, Predicates, Queries, Statements, etc..,

Clauses:  which are constituent components of statements and queries.

Expressions: which can produce either scalar values or tables consisting of columns and rows of data.

Predicates: which specify conditions that can be evaluated to SQL three-valued logic (3VL) or Boolean (true/false/unknown) truth values and which are used to limit the effects of statements and queries, or to change program flow.

Queries: which retrieve the data based on specific criteria. This is the most important element of SQL.

Statements: which may have a persistent effect on schemata and data, or which may control transactions, program flow, connections, sessions, or diagnostics.  

• SQL statements also include the semicolon (";") statement terminator. Though not required on every platform, it is defined as a standard part of the SQL grammar. 

Insignificant whitespace is generally ignored in SQL statements and queries, making it easier to format SQL code for readability.

SQL Language Categories:-
SQL is classified into 4 major categories as below:-

DDL - Data Definition Language

DML - Data Manipulation Language

DCL - Data Control Language

TCL - Transaction Control Language

We will look at it in-detail later posts..