SQL
WHERE Clause

WHERE clause is used to filter records, and extract only the specific data that we want in any special case.

Operators of WHERE Clause

Below are operators that could be used with where clause in SQL.

Operator	Description
=	Equal
< >	Not equal its is some time is used as !
>	Greater than
<	Less than
>=	Greater than or equal
<=	Less than or equal
BETWEEN	Between a certain range
LIKE	Search for a pattern
IN	To specify multiple possible values for a column

Basic Syntax

SELECT statement can be used to select single column from a database.

Let’s assume we have a table named as customers and this table having multiple columns like customer_name, customer_address, customer_contact_no. We want to select all the data of customer the above select statement will be utilized.

Copy Code



	SELECT column1, column2....columnN
	FROM table_name
	WHERE condition;

Examples

Select all the customers who belongs to Pakistan.

Copy Code



	SELECT * FROM Customers
	WHERE Country='pakistan';

Select a customer by ID.

Copy Code



	SELECT * FROM Customers
	WHERE CustomerID=20;

SQL
DISTINCT Statement

The SELECT DISTINCT statement is used to return only different values.

SELECT DISTINCT Statement

Copy Code



    SELECT DISTINCT Country FROM Customers;

SQL
SELECT Statement

There are multiple ways to use SELECT statement in SQL.

Select Single Columns

SELECT statement can be used to select single column from a database.

For instance, If we only want to see the customers names from customers table.

Copy Code



	SELECT column_name FROM table_name;

Select Multiple Columns

SELECT statement can be used to select single column from a database.

Copy Code



	SELECT column1, column2....columnN
	FROM table_name;

Select All Columns

SELECT statement can used to select whole data from a database.

Copy Code



	SELECT * FROM table_name;

SQL
DELETE Statement

DELETE statement is used to delete the records of a table.

Basic Syntax

Copy Code

DELETE FROM table_name WHERE condition;

Example

Specific Record

If you want to delete a specific customer details from customer table:

Copy Code


 

    DELETE FROM Customers WHERE CustomerName='john';

All Record

If you want to delete all the records of customer table:

Copy Code



    DELETE FROM Customers;

SQL
UPDATE Statement

UPDATE statement is used to edit the records of a table.

with WHERE

Syntax

Copy Code


 

    UPDATE table_name
    SET column1 = value1, column2 = value2, ...
    WHERE condition;

Example

Copy Code


  UPDATE Customers
	SET CustomerName = 'john', City= 'Austria'
	WHERE CustomerID = 6;

without WHERE

Whenever we use UPDATE Statement without WHERE clause it will Update all the records in the table.

Syntax

Copy Code



    UPDATE table_name
    SET column1 = value1, column2 = value2...;

Example

Copy Code


 

  UPDATE Customers
  SET CustomerName='john';

SQL
INSERT INTO Statement

INSERT INTO statement is used to insert the records in table. We can insert records in table in two ways, the most commonly used way for insert is to specify both the column names and values.

All Columns

In this method there is no need to specify the column names in SQL query, however make sure the order of the values and columns.

Syntax

Copy Code


  INSERT INTO table_name
  VALUES (value1, value2, value3, ...);

Example

Copy Code


  INSERT INTO Customers
  VALUES ('john', 'Michel john ', 'St 55', 'louse angelus', '4900', 'USA');

Selective Columns

Syntax

Copy Code


  INSERT INTO table_name (column1, column2, column3, ...)
  VALUES (value1, value2, value3, ...);

Example

Copy Code


    INSERT INTO Customers (CustomerName, ContactName, Address, City, PostalCode, Country)
    VALUES ('john', 'Michel john ', 'St 55', 'louse angelus', '4900', 'USA');

Introduction to
SQL

SQL is a standard language for sorting, manipulating and retrieving data from databases. SQL stands for Structured Query Language that let you access and manipulate databases.

Power of SQL:

SQL can execute queries against a database
SQL is used to insert data into a database
SQL is used to retrieve data from a database
SQL is used to update/edit data of a database
SQL is used to delete/remove data of a database
SQL is used to create database and tables
SQL is used to create stored procedures
SQL is used to create view in a database
SQL is used to set permission on tables, procedures and views

Commands of SQL

Below are some most important and basic commands of SQL.

Command	Description
SELECT	It extracts data from a database
UPDATE	It updates data in a database
DELETE	It deletes data from a database
INSERT INTO	It inserts new data into a database
CREATE DATABASE	It creates a new database
ALTER DATABASE	It modifies a database
CREATE TABLE	It creates a new table
ALTER TABLE	It modifies a table
DROP TABLE	It deletes a table
CREATE INDEX	It creates an index
DROP INDEX	It deletes an index

HTML
YouTube

YouTube videos can be embedded into website by using either the iframe or object HTML tags.

YouTube by Iframe

Below example will demonstrate the basic architecture of HTML Comments.

Copy Code


<!doctype html>  
<html>
    <head>
        <title>YouTube by Iframe</title>
    </head>

    <body>
        <iframe src="https://youtu.be/XDYn3ML3beA" width="560" height="315" frameborder="0" allowfullscreen></iframe>
    </body>
</html>

YouTube by Object

Below example will demonstrate the basic architecture of HTML Comments.

Copy Code


<!doctype html>  
<html>
    <head>
        <title>YouTube by Object</title>
    </head>

    <body>
        <object data="https://youtu.be/XDYn3ML3beA" width="560" height="315"></object>
    </body>
</html>

HTML
Video

The HTML <video> tag is used to embed a media player which supports video playback into the website.

Video Breakdown

Here is the breakdown of HTML Video.

Video Attributes

Attribute	Description
src	It specifies the URL
width	It specifies the width
autoplay	It specifies that the video will play automatically
controls	It specifies that the video controls get displayed
height	It specifies the height
loop	It specifies that the video will start again every time after finish
muted	It specifies that the audio should be muted
poster	It specifies the image to be shown while the video is downloading
preload	It specifies how and when the video file should load

Video Example

Below example will demonstrate the basic architecture of HTML Video.

Copy Code


<!doctype html>  
<html>
    <head>
        <title>HTML Comment Example</title>
    </head>
  
    <body>
        <video controls>
            <source src="intro.webm" type='video/webm;codecs="vp8, vorbis"'/>
        </video>
    </body>
</html>

HTML
Tables

Tables are utilized in HTML documents (web pages) to present tabular data. The HTML tables allow website authors to arrange data or record like text, links, images, other tables, etc. into rows and columns of cells.

In HTML, we create tables using the <table> tag, in conjunction with the <tr> and <td>.

Each set of <tr> tags (opening and shutting tags) represents a row within the table that they’re nested in. And each set of <td> tags represents a table data cell among the row that they’re nested in.

You can conjointly add table headers using the <th> element.

Breakdown

Here is the breakdown of HTML Table

Table Example

Below example will demonstrate the basic architecture of Table

Copy Code


<!doctype html>  
<html>
    <head>
        <title>Table Example</title> 
    </head>
  
    <body>
        <table>
            <tr>
                <th>Heading</th>
            </tr>
       
            <tr>
                <td>Content</td>
            </tr>
        </table>
    </body>
</html>

SQL WHERE Clause

Operators of WHERE Clause

Basic Syntax

Examples

SQL DISTINCT Statement

SELECT DISTINCT Statement

SQL SELECT Statement

Select Single Columns

Select Multiple Columns

Select All Columns

SQL DELETE Statement

Basic Syntax

Example

Specific Record

All Record

SQL UPDATE Statement

with WHERE

Syntax

Example

without WHERE

Syntax

Example

SQL INSERT INTO Statement

All Columns

Syntax

Example

Selective Columns

Syntax

Example

Introduction to SQL

Commands of SQL

HTML YouTube

YouTube by Iframe

YouTube by Object

HTML Video

Video Breakdown

Video Attributes

Video Example

HTML Tables

Breakdown

Table Example

SQL
WHERE Clause

SQL
DISTINCT Statement

SQL
SELECT Statement

SQL
DELETE Statement

SQL
UPDATE Statement

SQL
INSERT INTO Statement

Introduction to
SQL

HTML
YouTube

HTML
Video

HTML
Tables