INTRODUCTION TO SQL

SQL stands for Structured Query Language . It is Pronounced as see-kwell or s-q-l. SQL is designed By IBM. SQL is developed in 1986.SQL is the best DataBase used today for storing data.



SQL is language used to create and manipulate Relational Databases. By Relational Database are sets of information stored in relations or tables.

The main difference between DBMS and RDBMS is
In DBMS data is stored in DBMS accepts the ‘flat file’ data and In RDBMS data is organised in tables in rows and columns that relates each other.
 In DBMS there is not relation between data. In RDBMS we can relate one table data with other using Foreign 
key.
DBMS does not have constraints and RDBMS consist of constraints :-

* Not Null
* Check
* UNIQUE
* Primary Key
* Foreign Key

EXAMPLE OF CONSTRAINTS :-

create table employee
(
Emp_Id varchar(10), Not NULL Primary Key
age int ,
check(age>18),
)

Microsoft SQL SERVER And Visual Studio

Microsoft SQL server is Relational Database Management System used to store data in database and to manipute data using different queries.Microsoft SQL server Automatically installed When we install Microsoft Visual studio .

INTERFACING SQL SERVER WITH VISUAL STUDIO

To interface SQL server with visual studio we require Microsoft SQL Server Management Studio software. You can freely download it from link below :-

http://splashurl.com/lwkngvl

INTRODUCTION TO VISUAL STUDIO

Microsoft Visual studio is a Software Developed by Microsoft to Develop console and GUI(Graphical User Interface) applications. It is also used for creating Web Applications and Web services.
The Major feature of Visual Studio is that it is Not Case Sensitive Language. It also consist of Intellisense window that suggest the code that can be used at that particular time.Microsoft visual studio has another very important function that it contains multiple programming languages. Current Microsoft Visual Studio uses Three languages :-


* C#
* Visual Basic
* j#

Microsoft Introduced .net framework with visual studio software. .NET Framework Includes :-

* CLR -COMMON LANGUAGE RUNTIME :- CLR is Multilanguage runtime engine used to run codes of different languages. CLR is an Execution engine that takes the MSIL (Microsoft Intermediate Language ) code as input and converts it into Native code. Native code is codi in Machine Language.  MSIL code is given to CLR is generated by compiler. 

CLR CODE EXECUTION PROCESS




* When we compile a programme written in any programming language supported by .net Then compiler first converts that code into Microsoft Intermediate Language (MSIL).

* MSIL code consist of two parts 

-- Data
-- Metadata

Data + Metadata is stored in assenbly file with extension ".assembly". This Assembly file consist of PEF(Portable Executable format)

* PEF(Portable Executable format):- It is a file format for executable,object code, DLL's and Font Files . The word Portable means it is adaptable or changable to different windows achitecutres. This file contains information for Operating Systems to load Exe file . 

PEF generally in .NET loads MSIL code and metadata . Metadata describes all classes and class members that are defined in the assembly. The metadata contains complete description of method or function along with class.

*  Then MSIL code is given to JUST IN TIME Compiler that translates the code from MSIL code to Native Code

* After code is converted to Native code, it is sent to .NET Runtime Manger 

* .NET Runtime Manger  then performs the security check on it to ensure code has permission to access the Availaible resources.