Database

PHP support variety of database management systems, including :

- MySQL - PostgreSQL

- Oracle - Microsoft Access

MySQL very fast

very reliable

very feature-rich open-source RDBMS

Every MySQL database is composed of :

one or more tables.

These tables, which:

structure data into rows and columns,

are what lend organization to the data.

CREATE DATABASE testdb;

CREATE TABLE `symbols`

(     `id` int(11) NOT NULL auto_increment,     `country` varchar(255) NOT NULL default '',     `animal` varchar(255) NOT NULL default '',     PRIMARY KEY  (`id`) )

INSERT INTO `symbols` VALUES (1, 'America', 'eagle'); INSERT INTO `symbols` VALUES (2, 'China', 'dragon'); INSERT INTO `symbols` VALUES (3, 'England', 'lion'); INSERT INTO `symbols` VALUES (4, 'India', 'tiger'); INSERT INTO `symbols` VALUES (5, 'Australia', 'kangaroo'); INSERT INTO `symbols` VALUES (6, 'Norway', 'elk');

FROM My SQL

Retrieve data from My Sql Database in PHP

<?php

// set database server access variables: $host = "localhost"; $user = "test"; $pass = "test"; $db = "testdb";

// open connection $connection = mysql_connect($host, $user, $pass) or die ("Unable to connect!");

// select database mysql_select_db($db) or die ("Unable to select database!");

// create query $query = "SELECT * FROM symbols";

// execute query $result = mysql_query($query) or die ("Error in query: $query. ".mysql_error());

Cont…

// see if any rows were returned if (mysql_num_rows($result) > 0) {     // yes     // print them one after another     echo "<table cellpadding=10 border=1>";     while($row = mysql_fetch_row($result)) {         echo "<tr>";         echo "<td>".$row[0]."</td>";         echo "<td>" . $row[1]."</td>";         echo "<td>".$row[2]."</td>";         echo "</tr>";     }     echo "</table>"; } else {     // no     // print status message     echo "No rows found!"; } // free result set memory mysql_free_result($result); // close connection mysql_close($connection); ?>

OUTPUT

mysql_fetch_array() Returns an array that corresponds to the fetched row and moves the internal data pointer ahead.

mysql_fetch_row() returns a numerical array that corresponds to the fetched row and moves the internal data pointer ahead.

mysql_fetch_assoc() returns an associative array that corresponds to the fetched row and moves the internal data pointer ahead. mysql_fetch_assoc() is equivalent to calling mysql_fetch_array() with MYSQL_ASSOC for the optional second parameter. It only returns an associative array.

mysql_fetch_object() returns an object with properties that correspond to the fetched row and moves the internal data pointer ahead.

mysql_fetch_array()<?php $host = "localhost"; $user = "root"; $pass = "guessme"; $db = "testdb"; $connection = mysql_connect($host, $user, $pass) or die ("Unable to connect!"); // get database list $query = "SHOW DATABASES"; $result = mysql_query($query) or die ("Error in query: $query. ".mysql_error()); echo "<ul>"; while ($row = mysql_fetch_array($result)) {     echo "<li>".$row[0];     // for each database, get table list and print     $query2 = "SHOW TABLES FROM ".$row[0];     $result2 = mysql_query($query2) or die ("Error in query: $query2. ".mysql_error());     echo "<ul>";     while ($row2 = mysql_fetch_array($result2)) {         echo "<li>".$row2[0]; }     echo "</ul>"; } echo "</ul>"; // get version and host information echo "Client version: ".mysql_get_client_info()."<br />"; echo "Server version: ".mysql_get_server_info()."<br />"; echo "Protocol version: ".mysql_get_proto_info()."<br />"; echo "Host: ".mysql_get_host_info()."<br />"; // get server status $status = mysql_stat(); echo $status; // close connection mysql_close($connection); ?>

OUTPUT

mysql_fetch_row()

// see if any rows were returned if (mysql_num_rows($result) > 0) {      // yes      // print them one after another      echo "<table cellpadding=10 border=1>";      while(list($id, $country, $animal)  = mysql_fetch_row($result)) {           echo "<tr>";           echo "<td>$id</td>";           echo "<td>$country</td>";           echo "<td>$animal</td>";           echo "</tr>";      }      echo "</table>"; } else {      // no      // print status message      echo "No rows found!"; }

OUTPUT

mysql_fetch_assoc()

// see if any rows were returned if (mysql_num_rows($result) > 0) {     // yes     // print them one after another     echo "<table cellpadding=10 border=1>";     while($row = mysql_fetch_assoc($result)) {         echo "<tr>";         echo "<td>".$row['id']."</td>";         echo "<td>".$row['country']."</td>";         echo "<td>".$row['animal']."</td>";         echo "</tr>";     }     echo "</table>"; } else {     // no     // print status message     echo "No rows found!"; }

OUTPUT

mysql_fetch_object()

// see if any rows were returned if (mysql_num_rows($result) > 0) {     // yes     // print them one after another     echo "<table cellpadding=10 border=1>";     while($row  = mysql_fetch_object($result)) {         echo "<tr>";         echo "<td>".$row->id."</td>";         echo "<td>".$row->country."</td>";         echo "<td>".$row->animal."</td>";         echo "</tr>";     }     echo "</table>"; } else {     // no     // print status message     echo "No rows found!"; }

OUTPUT

Form application in php and mysql database

<html> <head> <basefont face="Arial"> </head> <body>

<?php

if (!isset($_POST['submit'])) { // form not submitted ?>

    <form action="<?=$_SERVER['PHP_SELF']?>" method="post">     Country: <input type="text" name="country">     National animal: <input type="text" name="animal">     <input type="submit" name="submit">     </form>

Cont…

<?php } else { // form submitted // set server access variables     $host = "localhost";     $user = "test";     $pass = "test";     $db = "testdb";      // get form input     // check to make sure it's all there     // escape input values for greater safety     $country = empty($_POST['country']) ?

die ("ERROR: Enter a country") : mysql_escape_string($_POST['country']);     $animal = empty($_POST['animal']) ?

die ("ERROR: Enter an animal") : mysql_escape_string($_POST['animal']);

    // open connection     $connection = mysql_connect($host, $user, $pass) or die ("Unable to connect!");

Cont…

// select database     mysql_select_db($db) or die ("Unable to select database!");          // create query     $query = "INSERT INTO symbols (country, animal) VALUES ('$country', '$animal')";          // execute query     $result = mysql_query($query) or die ("Error in query: $query. ".mysql_error());          // print message with ID of inserted record     echo "New record inserted with ID ".mysql_insert_id();          // close connection     mysql_close($connection); } ?>

</body> </html>

OUTPUT

mysqli library<html> <head> <basefont face="Arial"> </head> <body>

<?php

// set server access variables $host = "localhost"; $user = "test"; $pass = "test"; $db = "testdb";

// create mysqli object // open connection $mysqli = new mysqli($host, $user, $pass, $db);

// check for connection errors if (mysqli_connect_errno()) {     die("Unable to connect!"); }

// create query $query = "SELECT * FROM symbols";

if ($result = $mysqli->query($query)) {     // see if any rows were returned     if ($result->num_rows > 0) {         // yes         // print them one after another         echo "<table cellpadding=10 border=1>";         while($row = $result->fetch_array()) {             echo "<tr>";             echo "<td>".$row[0]."</td>";             echo "<td>".$row[1]."</td>";             echo "<td>".$row[2]."</td>";             echo "</tr>";         }         echo "</table>";     }     else {         // no         // print status message         echo "No rows found!";  }     // free result set memory     $result->close(); } else {     // print error message     echo "Error in query: $query. ".$mysqli->error; } // close connection $mysqli->close(); ?> </body> </html>

OUTPUT

Delete record from mysqli library<?php

// set server access variables $host = "localhost"; $user = "test"; $pass = "test"; $db = "testdb";

// create mysqli object // open connection $mysqli = new mysqli($host, $user, $pass, $db);

// check for connection errors if (mysqli_connect_errno()) {     die("Unable to connect!"); }

// if id provided, then delete that record if (isset($_GET['id'])) { // create query to delete record     $query = "DELETE FROM symbols WHERE id = ".$_GET['id'];

Cont…

// execute query     if ($mysqli->query($query)) {     // print number of affected rows     echo $mysqli->affected_rows." row(s) affected";     }     else {     // print error message     echo "Error in query: $query. ".$mysqli->error;     } } // query to get records $query = "SELECT * FROM symbols";

Cont…

// execute query if ($result = $mysqli->query($query)) {     // see if any rows were returned     if ($result->num_rows > 0) {         // yes         // print them one after another         echo "<table cellpadding=10 border=1>";         while($row = $result->fetch_array()) {             echo "<tr>";             echo "<td>".$row[0]."</td>";             echo "<td>".$row[1]."</td>";             echo "<td>".$row[2]."</td>";             echo "<td><a href=".$_SERVER['PHP_SELF']."?id=".$row[0].">Delete</a></td>";             echo "</tr>";         }     }     // free result set memory     $result->close(); } else {     // print error message     echo "Error in query: $query. ".$mysqli->error; } // close connection $mysqli->close(); ?>

OUTPUT

THE END