PHP FUNCTION DISCUSSION BLOG: May 2013

Thursday, May 16, 2013

How to fetch records from Mysql Databae

The important technique in php is to fetch records from the database to list the data you need to used following php functions

mysql_connect : to connect the mysql server with apache server
mysql_select_db : to connect to a particular database in the mysql server
mysql_query : to fire a query in the database.
mysql_num_rows to find the number of records in a recordset which is derived from query fired.
mysql_fetch_array to fetch array from record set.
mysql_fetch_assoc to fetch row from associative array.
mysql_fetch_row to fetch row from record set.
mysql_fetch_object to fetch the data as object generally use to fetch large data
mysql_close close mysql connection

Step by step we can use this functions to fetch data from Database

Using while loop

$recordset = mysql_query("select * from DBTABLE");
while ($record= mysql_fetch_array($recordset ) {
                echo "user_id: ".$record["db_field_name"]."<br />\n"; // as in database
echo "user_id: ".$record[0]."<br />\n"; // in key value as in array
      }

This will fetch the database values from dbtable and retrieve list of particular db_field_name

Using for while loop and mysql_fetch_object
$recordset = mysql_query("select * from DBTABLE");

while ($record= mysql_fetch_object($recordset )) {
   echo $record->db_field_name;
}

Using for loop
$record= mysql_fetch_array($recordset );
$count=count($record) ;
for($i = 0;$i< $count ; $i ++)
{
                 echo "user_id: ".$record[$i]["db_field_name"]."<br />\n"; // as in database
}
we will go through other function later...

Tuesday, May 14, 2013

function mysql_connect

The most important function that is used in the php coding is mysql_connect .

This is function used to connect Mysql server with Apache server (PHP).

The syntax for it goes as

mysql_connect ( localhost,username,password)

where the localhost refers to Mysql HOST

username :Mysql username
password ;Mysql password

Example of mysql_connect

<?php
    $link = mysql_connect("localhost", "username", "password")
        or die("Could not connect");
    print ("Connected successfully");
    mysql_close($link);
?>

Similar function which is used for connecting the Mysql server is mysql_pconnect

Mysql_pconnect establishes a persistent connection

In Mysql_connect after the script that calls it has finished it will be closed. but mysql_pconnect will continue to hold the connection until it is closed manually by the user.

Monday, May 13, 2013

array_key_exists()

function It is a array function which is used to check if the given key or index exists in the array.

To better understand the function let us see an example

$your_array = array("one" => 1, "two" => 4);
if (array_key_exists("one", $your_array)) {
echo "The 'one' element is in the array";
}

if the key exists in the array it will return true other wise it would return false

Use of array_key_exists()

This function is widely use to save programmers time in search function.

Most of the array function contain a wide range of argument which can be used to minimize source code.

Wednesday, May 8, 2013

What is PHP

PHP is a very simple and interactive programming language.It is simple to learn and easy to understand.popularly known as "Personal Home Page" but it does not mean PHP stands for it.it stands as HYPERTEXT PRE-PROCESSOR.

To learn PHP, our basic requirement is knowledge of HTML ,JAVASCRIPT, and overview of C and C++.

To start php in a code you need to declare <?php
And to end a php code you need to declare ?>

php is very near to basic C language so it is simple to learn. but PHP supports OOPS i.e Object oriented programming.

Main Benefit of PHP is it is an open source and available to all freely.

The basic structure of HTML goes like this

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
   "http://www.w3.org/TR/html4/strict.dtd">
<HTML>
   <HEAD>
      <TITLE>Mytitle</TITLE>
   </HEAD>
   <BODY>
      <P>My Content
   </BODY>
</HTML>

when we want to use the php code we can just modify this like

<HTML>
   <HEAD>
        <title>Mytitle</title>
  </HEAD>
    <BODY>
<P>
        <?php 
        echo "My Content"; 
        ?>

   
</BODY>
</HTML>

Now save the file as some "filename.php" and execute the file

in the localhost which would give OUTPUT as below in Browser.

My Content