How To Connect To A Database In PHP

Creating a Connection between PHP and Mysql

To update,create,change,insert .. a database you need to create a connection between mysql and php.
To connect with a database we can use the function mysql_connect()
Function mysql_connect() need 3 main parameters they are server name user name and password.
Code to Connect with a database
<?php
$server="localhost";  // SERVER NAME Default is localhost
$user  = "root";     // USER NAME Default is root
$pass  = "";        // PASSWORD  Default is nothing
$connection = mysql_connect($server,$user,$pass);
if (!$connection)
  {
  echo "An error occurred";
  }
mysql_query("") // INSERT YOUR SQL QUERY  BETWEEN ""
mysql_close($connection);
?>

Conditions In PHP

Conditions in php
If  Else
If else statements are used to check a condition is true or false and execute a group of statements if true other wiseexecute some other statements.The if statement also sub divided to Else if .... else.It is used to check more than one conditions in the same  set of codes.

if (codition)

{ set of codes to execute when condition is true}

else

{set of codes to execute when condition is false }

if (codition_one)

{ set of codes to execute when condition is true}

elseif

{set of codes to execute when condition_one is false and condition_two is true}

else

{set of codes to execute when conditions are false}

Eg:

<?php
$a=1;
if($a==1)
{
echo "number = 1";
}
elseif($a==0)
{ echo "Number is not zero";


}
else
echo "number is not 0 nor 1";
?>

Switch
Simply a Switch statement  is used to execute a group of codes when anyone of condition matches.

switch (some_variable)

case 1:

break;

case 2:

break; 
.
.
.
.
default :

Eg:

<?PHP
$week=2;
switch($week)
{
case 1:
echo "day is Sunday";
break;
case 2 :
echo "day is Monday";
break;
case 3:
echo "day is Tuesday ";
break;
case 4:
echo "day is Wednesday";
break;
case 5:
echo "day is Thursday ";
break;
case 6 :
echo "day is Friday";
break;
case 7:
echo "day is Saturday ";
break;
default :
echo "Invalid choise";
}

 Output is day is Monday

Declare Or Define Variables In PHP

We can store values like characters,strings,integer,float values everything in a variable.In other languages we need to specify the variables type like int a or Dim a as integer etc.But in php we can store any value in a variable without specifying its type.It makes php easier than other languages.To declare a php variable we uses a $  symbol at beginning of variable name.
A variable can be defined as
$variable_name=Variables_value
Eg:
$a=1;
$a='a';
$a="a";
$a=111.11;

Sample Code to try .

<?php
$number=10;
$text="my name";
Echo $number;
Echo "<br>"; // for a new line
Echo $text;
?>

result will be

10

My name

Main Rules must obey to define variable names
Variable name shouldn't contain SPACE
$a and $A are different
You may use 0-9 a-z A-Z and _  to declare a variable name