SQL: Structured Query Language

By: Gonzales, Brian Gabriel E.

What is SQL?

- Structured Query Language, or SQL (pronounced "ess-que-el"), is a query language. A database can be communicated with using SQL. It is the preferred language for relational database management systems, claims ANSI (the American National Standards Institute). To update data in a database or to get data from a database, SQL statements are employed. Oracle, Sybase, Microsoft SQL Server, Access, Ingres, and other popular relational database management systems are only a few examples.

 

 SQL Commands

• 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