• MySQL is the most popular Open Source SQL database management system.


• MySQL is developed and supported by Oracle Corporation.


• MySQL is Relational DataBase System.


• MySQL is very fast, reliable, scalable, and easy to use DataBase Server.


• MySQL is named after co-founder Monty Widenius's daughter, My.


• MySQL connects to our tables using our own fast low-level routines.

mysql_connect and mysqli_connect() function are use to open a new connection to the MySQL server in PHP.

Syntax

mysql_connect(host, user, password);

or

mysqli_connect(host,username,password,dbname);

Parameters	Description
host	IP Address or host.
user	User name of MySQL.
password	password of MySQL.
dbname	Which Database to be used.

Example1:

<?php

mysql_connect("localhost", "user", "password") or die(mysql_error());

echo "Connected to MySQL <br />";

mysql_close(); //This function use for close the connection.

echo "Connection closed";

?>

Output :

Connected to MySQL
Connection closed

Example2 :

<?php

// Create connection
$con=mysqli_connect("localhost","username","password","php_db");

// Check connection
if (mysqli_connect_errno($con))
{
	echo "Connection Failed " . mysqli_connect_error();
}
else 
{
	echo "Connection Created";
}
mysqli_close($con);//Close Connection.

?>

Output :

Connection Created

CREATE DATABASE statement use to create a database table in MySQL.

Example :

<?php
$con=mysqli_connect("localhost","username","password");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Connection Failed" . mysqli_connect_error();
  }

 // Create database
$sql="CREATE DATABASE php_db";
if (mysqli_query($con,$sql))
  {
  echo "Database php_db created successfully";
  }
else
  {
  echo "Error " . mysqli_error($con);
  }
?>

Output :

Database php_db created successfully

CREATE TABLE statement use to create a table in MySQL.

Example :

<?php

$con=mysqli_connect("localhost","username","password","php_db");
// Check connection
if (mysqli_connect_errno())
{
	echo "Conection Failed " . mysqli_connect_error();
}

// Create table
$sql="CREATE TABLE Employees(FirstName CHAR(30),LastName CHAR(30),Age INT)";

// Execute query
if (mysqli_query($con,$sql))
{
	echo "Employees table created successfully";
}
else
{
	echo "Error : " . mysqli_error($con);
}
?>

Output :

Employees table created successfully.

INSERT INTO statement use to add new records to a database table.

Example :

<?php

$con=mysqli_connect("localhost","username","password","php_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

mysqli_query($con,"INSERT INTO Employees (FirstName, LastName, Age)
VALUES ('fname', 'lname',35)");

mysqli_query($con,"INSERT INTO Employees (FirstName, LastName, Age) 
VALUES ('fname1', 'lname1',33)");

echo "Table Inserted";

mysqli_close($con);

?>

Output :

Table Inserted

SELECT statement use to select data from a database.

Example :

<?php

$con=mysqli_connect("localhost","username","password","php_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Connection Failed: " . mysqli_connect_error();
  }

$result = mysqli_query($con,"SELECT * FROM Employees");

while($row = mysqli_fetch_array($result))
  {
  echo $row['FirstName'] . " " . $row['LastName'];
  echo "
";
  }

mysqli_close($con);

?>

Output :

fname lname
fname1 lname1

WHERE clause use to extract only those records that fulfill a specified criteria.

Example :

<?php

$con=mysqli_connect("localhost","username","password","php_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Conection Failed " . mysqli_connect_error();
  }

$result = mysqli_query($con,"SELECT * FROM Employees
WHERE FirstName='fname'");

while($row = mysqli_fetch_array($result))
  {
  echo $row['FirstName'] . " " . $row['LastName'];
  echo "
";
  }

?>

Output :

fname lname

ORDER BY keyword use to sort the data in a recordset.

The sorting of the records in ascending order by default.

Example :

<?php

$con=mysqli_connect("localhost","username","password","php_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "onnection Failed: " . mysqli_connect_error();
  }

$result = mysqli_query($con,"SELECT * FROM Employees ORDER BY age");

while($row = mysqli_fetch_array($result))
  {
  echo $row['FirstName'];
  echo " " . $row['LastName'];
  echo " " . $row['Age'];
  echo "
";
  }

mysqli_close($con);

?>

Output :

fname1 lname1 33
fname lname 35

UPDATE statement use to update existing records in a table.

Example :

<?php

$con=mysqli_connect("localhost","username","password","php_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Connection Failed: " . mysqli_connect_error();
  	  }

mysqli_query($con,"UPDATE Persons SET Age=36
WHERE FirstName='fname' AND LastName='lname'");

echo " Data Updated. ";

mysqli_close($con);

?>

Output :

Data Updated.

DELETE FROM statement use to delete records from a database table.

Example :

<?php

$con=mysqli_connect("localhost","username","password","php_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Connection Failed: " . mysqli_connect_error();
  	  }

mysqli_query($con,"DELETE FROM Persons WHERE LastName='lname'");

echo "Data Deleted. ";
mysqli_close($con);

?>

Output :

Data Deleted.