STRUCTURED QUERY LANGUAGE(SQL) Created by: B Mokshagna Reddy (BMR) SQL DATA DEFINITION AND DATATYPES SQL Schema: An SQL schema is identified by a schema name and includes an authorization identifier name to indicate user or account who owns the schema, as well as descriptor for each elements in the schema. Schema creation with authorization: CREATE SCHEMA DATABASE_NAME AUTHORIZATION IDENTIFIER; Eg: CREATE SCHEMA COMPANY AUTHORIZATION ‘JSMITH’; Catalog: Named collection of schemas. Data Definition, Constraints, and Schema Changes Used to CREATE, DROP, and ALTER the descriptions of the tables (relations) of a database Creating a Database Syntax: CREATE DATABASE database_name; Creating a Table Syntax CREATE TABLE table_name (Column_name datatype[(size)], Column_name datatype[(size)], ); Specifies a new base relation by giving it a name, and specifying each of...
HTML INTRODUCTION
Created by: B Mokshagna Reddy (BMR)
INTRODUCTION
➢HTML stands for Hyper Text Markup Language.➢HTML is the standard markup language for creating Web pages.
➢HTML describes the structure of a Web page.
➢HTML consists of a series of elements.
➢HTML elements tell the browser how to display the content.
➢HTML elements label pieces of content such as "this is a heading", "this is a paragraph", "this is a link", etc.
Web or Internet?
➢It is important to understand that the Internet and the Web is not the same thing.➢The Internet is a collection of computers and other devices connected by equipment that allows them to communicate with each other.
➢The Web is a collection of software and protocols that has been installed on most, if not all, of the computers on the Internet.
The World Wide Web
➢Tim Berners Lee and his group proposed a new protocol for the Internet whose intention was to allow scientists around the world to use the Internet to exchange documents describing their work.➢The proposed new system was designed to allow a user anywhere on the Internet to search for and retrieve documents from the databases on any number of different document-serving computers.
➢The system used hypertext, which is text with embedded links to text in other documents to allow non-sequential browsing of textual material.
➢The units of web are referred as pages, documents and resources.
➢Web is merely a vast collection of documents, some of which are connected by links.
➢These documents can be accessed by web browsers and are provided by web servers.
WEB BROWSERS
➢Documents provided by servers on the Web are requested by browsers, which are programs running on client machines.➢They are called browsers because they allow the user to browse the resources available on servers.
➢Mosaic was the first browser with a graphical user interface.
➢A browser is a client on the Web because it initiates the communication with a server, which waits for a request from the client before doing anything.
➢In the simplest case, a browser requests a static document from a server.
➢Examples: Internet Explorer, Mozilla Firefox, Netscape Navigator, Google Chrome, Opera etc.,
WEB SERVERS
➢Web servers are programs that provide documents to requesting browsers.➢All the communications between a web client and a web server use the HTTP.
➢When a web server begins execution, it informs the OS under which it is running & it runs as a background process.
➢A web client or browser, opens a network connection to a web server, sends information requests and possibly data to the server, receives information from the server and closes the connection.
➢The primary task of web server is to monitor a communication port on host machine, accept HTTP commands through that port and perform the operations specified by the commands.
➢When the URL is received, it is translated into either a filename or a program name.
HTML Page Structure
➢The <html> and <!DOCTYPE html> declaration defines that this document is an HTML5 document➢The <html> element is the root element of an HTML page.
➢The <head> element contains meta information about the HTML page.
➢The <title> element specifies a title for the HTML page (which is shown in the browser's title bar or in the page's tab).
➢The <body> element defines the document's body, and is a container for all the visible contents, such as headings, paragraphs, images, hyperlinks, tables, lists, etc
The <!DOCTYPE> Declaration
➢The <!DOCTYPE> declaration represents the document type, and helps browsers to display web pages correctly.➢It must only appear once, at the top of the page (before any HTML tags).
➢The <!DOCTYPE> declaration is not case sensitive.
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