SQL Introduction by ranjithsukanya


									SQL Introduction

Quick Introduction to SQL: SQL is Structure Query Language. This Query language is used to
connect with the database. It is considered as standard language for relation database
management systems according to (American National Standards institute). The SQL have own
statement, which helps you to perform various tasks such as insert, update or retrieve the data
from database, In others word it is a database sub language for querying and modifying relational
database. The common relational database using SQL are: Oracle, Microsoft SQL
Server,Ingress,Access,etc.Normally. The most database use SQL ,but these database have their
own property, which are used on their system. The standard common command used in SQL are"
Select"," Insert"," Update","Delete","Create","Drop" and Truncate, which are performed on

Data Definition Language: The Data Definition language is used to create,alter,drop or delete a
table in database. This include a index through which you can make a link between table in
database. The list of Data Definition language are as given below

Statements Description
            The Create Table is used to create a
          table in database
Alter          The Update is used to alter the table
                The Drop Table is used to drop
              table in database

 Data Manipulation Language :The Data Manipulation Language is used to select, insert
into,delete,update from database table. The following keyword perform the particular task are
given below:

Statements       Description
              The Select is used to display the records
              available in table.
              The Update is used to modify or change
              in table
Delete        The Delete is used to record from table
              The Insert into is used to add records
Insert into
              into table
Structure of SQL Language

The SQL is a keyword based language. Each statement in SQL start with a unique keyword. The
SQL statements include a clauses begin with a keyword. SQL syntax is independent of case-

Syntax for SQL Statement

 1) Elements of database are tables,columns,views,user,schemas,names,which begin with a
letter(a-z), digits(0-9) and underscore(_).

2)literals used in SQL Statement are quoted strings,datetime values, numeric values.

3)delimiter are + -,( ),=,<>,*,||,?;

Names in the database is case sensitive, include spaces and delimiters, include keywords
surrounds with double quotation marks("").For Example


The next Tutorial shows you more example on each statements of SQL.

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