What is SQL?

SQL (pronounced “ess-que-el”) stands for Structured Query Language. SQL is used to communicate with a database. SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987. SQL lets you access and manipulates databases. Some common relational database management systems that use SQL are Oracle, Sybase, Microsoft SQL Server, Access, Ingres, etc.

 

What Can SQL do?

Most common usage of SQL involves-

  • SQL can execute queries against a database
  • SQL can retrieve data from a database
  • SQL can insert records in a database
  • SQL can update records in a database
  • SQL can delete records from a database
  • SQL can create new databases and tables in the database

 

Why we need it?

  • SQL is used everywhere.
  • It’s in high demand because so many companies use it.
  • It is easy to use and gives quick access to information.
  • It is a gateway to other programming.
  • Although there are alternatives, SQL is not going anywhere.

 

Some of The Most Important SQL Commands are-

SELECT – extracts data from a database

UPDATE – updates data in a database

DELETE – deletes data from a database

INSERT INTO – inserts new data into a database

CREATE DATABASE – creates a new database

ALTER DATABASE – modifies a database

CREATE TABLE – creates a new table

ALTER TABLE – modifies a table

DROP TABLE – deletes a table

CREATE INDEX – creates an index (search key)

DROP INDEX – deletes an index

 

Use this link for a list of all SQL commands.

 

This link is a good video lesson to learn SQL.

 

And for practising SQL this link is excellent.

 

The Data School
Author: The Data School