WHAT IS SQL

SQL:

Abbrivation: Structured Query Language, an international standard for database manipulation.

SQL is a computer language designed to manipulate data in RDBMS(Relational database management system).

SQL is an ANSI Standard,it is devoloped by IBM.

SQL is divided into three basic parts:

  • DDL
  • DML
  • DCL

DDL: Data Definition Language. Read more about DDL here

DML: Data manipulation language. Read more about DML here

DCL: Data Control Language. Read more about DCL here

SQL Database contains objects like Tables, Procedures, Views, Functions, Triggers etc..

Read more about SQL Server Objects here.

Tables contain columns which hold data of a single type. So each table constitutes of multiple columns of different datatype.

Read more about SQL Server Datatypes here.

Following are the few TASKS that can be done using SQL:

  • Create, Modify, Delete Databases
  • Create , Modify, Delete Database Objects such as
    Tables,Procedures,Views,Functions etc..
  • Grant, Revoke Permissions on Database Objects
  • Insert,Delete,Update records in Tables.
  • Create,Modify, Drop  Indexes,Triggers Etc.
  • Fetch data from the database Tables,views etc.
  • Execute Procedures , Functions Etc.

Simple SQL Query:


SELECT * FROM EMPLOYEE

The above query when executed gives all the records in the table Employee.

Further Reading: wiki