Steps for JSP request:

1. When the user goes to a JSP page web browser makes the request via internet.
2. JSP request gets sent to the Web server.
3. Web server recognises the .jsp file and passes the JSP file to the JSP Servlet Engine.
4. If the JSP file has been called the first time,the JSP file is parsed,otherwise Servlet is instantiated.
5. The next step is to generate a special Servlet from the JSP file. All the HTML required is converted to println statements.
6. The Servlet source code is compiled into a class.
7. The Servlet is instantiated,calling the init and service methods.
8. HTML from the Servlet output is sent via the Internet.
9. HTML results are displayed on the user's web browser

SQL SERVER – What is – DML, DDL, DCL and TCL – Introduction and Examples

SQL SERVER – What is – DML, DDL, DCL and TCL – Introduction and Examples

DML

DML is abbreviation of Data Manipulation Language. It is used to retrieve, store, modify, delete, insert and update data in database.

Examples: SELECT, UPDATE, INSERT statements

DDL

DDL is abbreviation of Data Definition Language. It is used to create and modify the structure of database objects in database.

Examples: CREATE, ALTER, DROP statements

DCL

DCL is abbreviation of Data Control Language. It is used to create roles, permissions, and referential integrity as well it is used to control access to database by securing it.

Examples: GRANT, REVOKE statements

TCL

TCL is abbreviation of Transactional Control Language. It is used to manage different transactions occurring within a database.

Examples: COMMIT, ROLLBACK statements

JSON Introduction

What is JSON?

•  JSON stands for JavaScript Object Notation.
•  JSON is lightweight text-data interchange format.
•  JSON is language independent.
•  JSON is "self-describing" and easy to understand.

JSON uses JavaScript syntax for describing data objects, but JSON is still language and platform independent. JSON parsers and JSON libraries exists for many different programming languages.

JSON format is a format similar to XML but usually it is shorter and easier to parse. Many web services now work with JSON. Using the new JSON library, you can parse and generate JSON strings easily.

Much like XML

• JSON is plain text
• JSON is "self-describing" (human readable)
• JSON is hierarchical (values within values)
• JSON can be parsed by JavaScript
• JSON data can be transported using AJAX

Much Unlike XML

• No end tag
• Shorter
• Quicker to read and write
• Can be parsed using built-in JavaScript eval()
• Uses arrays
• No reserved words

Why JSON?

For AJAX applications, JSON is faster and easier than XML:

Using XML

• Fetch an XML document
• Use the XML DOM to loop through the document
• Extract values and store in variables

Using JSON

• Fetch a JSON string
• eval() the JSON string