Learn SQL Programming

A DBMS is a software-based system that provides a management interface, which helps users control databases and data sources.

 Example:

                 A  building name, A  flat no in the building, A  road name, 

                An area name,  A state name

A Database Management System (DBMS) is software designed to store, retrieve, define and manage data in a database.

• The amount of data redundancy in stored data can be reduced.
• Stored data can be shared by a single or multiple users.
• Security of data can be simply implemented
• Standards can be set and followed

All modern database management systems like SQL, MS SQL Server, IBM DB2, ORACLE, My-SQL and Microsoft Access are based on RDBMS.

It is called Relational Data Base Management System (RDBMS) because it is based on relational model introduced by E.F. Codd.

SQL is a language that provides an interface to relation  database systems.

There are main components of SQL are as follows:

• DDL(Data Definition Language)
• DML(Data Manipulation Language)
• DCL(Data Control Language)
• DQL(Data Query Language)

  It is a set of SQL commands used to create,modify and delete database structures but not data.

    

    Example:

    Create, Alter, Drop, Truncate & Rename

It is the area of SQL that allows changing data within the database.

    Example:

                    Insert, Update, Delete

It is the component of SQL statement that control access to 

data and to database.

    Example:

                    Commit,Savepoint,Rollback,Grant

This command is the heart of SQL .

     Example:

                    Select Retrieve  data from the a database

[DDL & DML STATEMNTS]
Overview
DDL statements are used to create database, schema, constraints, users, tables etc.DML is Data Manipulation Language and is used to manipulate data. Examples of DML are insert, update and delete statements.
DDL & DML	SYNTAX	EXAMPLE
CREATE DATABASE   USE DATABASE	CREATE DATABASE databasename;   Use DBName	CREATE DATABASE testDB;   Use testDB
CREATE TABLE	CREATE TABLE table_name (     column1 datatype,     column2 datatype,     column3 datatype,    .... )	CREATE TABLE Persons (     PersonID int,     LastName varchar(255),     FirstName varchar(255),     Address varchar(255),     City varchar(255) )
INSERT	INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...)   INSERT INTO table_name VALUES (value1, value2, value3, ...)	INSERT INTO Customers (CustomerName, ContactName, Address, City, PostalCode, Country) VALUES ('Cardinal', 'Tom B. Erichsen', 'Skagen 21', 'Stavanger', '4006', 'Norway')   INSERT INTO Customers (CustomerName, City, Country) VALUES ('Cardinal', 'Stavanger', 'Norway')
UPDATE	UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition;	UPDATE Customers SET ContactName = 'Alfred Schmidt', City= 'Frankfurt' WHERE CustomerID = 1     UPDATE Customers SET ContactName='Juan' WHERE Country='Mexico'
DELETE	DELETE FROM table_name WHERE condition   DELETE FROM table_name	DELETE FROM Customers WHERE CustomerName='Alfreds Futterkiste'   DELETE FROM Customers
SELECT	SELECT column1, column2, ... FROM table_name   SELECT * FROM table_name	SELECT CustomerName, City FROM Customers   SELECT * FROM Customers