Autoreconnect class for database in php - php

Question

I am developing a class for Database access and query.
If database is accessible it is working correctly, But problem comes when somehow database is restarted.
Below is the code for library and its users code.
It is able to reconnect with database, but unable to select database. I have tried for 2,5 retry attempts from select_from_db function. But its throwing error Unable to select database test MySQL server has gone away. I am using Windows machine and in sleep time i am executing below command for restarting mysql.
net stop wampmysqld
net start wampmysqld
Please let me know for your suggestion and answers, so that i can improve on it.
<?php
class database {
private $host;
private $user;
private $pswd;
private $name;
private $db_handle;
private $error_msg;
function __construct($db_host, $db_user, $db_pswd, $db_name=NULL){
$this->host = $db_host;
$this->user = $db_user;
$this->pswd = $db_pswd;
$this->name = $db_name;
$this->db_handle = NULL;
$this->error_msg = NULL;
}
function connect(){
if(!is_null($this->db_handle)){
return True;
}
echo "Trying connection..\n";
$this->db_handle = mysql_connect($this->host, $this->user, $this->pswd);
if(!$this->db_handle){
$this->db_handle = NULL;
$this->error_msg = "Unable to connect to database : ".mysql_error();
return False;
}
else{
echo "\nconnected to database successfully!\n";
}
echo $this->name. "\n";
if(!is_null($this->name)){
$result = mysql_select_db($this->name, $this->db_handle);
if(!$result){
$this->db_handle = NULL;
$this->error_msg = 'Unable to select database '.$this->name.' '.mysql_error();
return False;
}
else{
echo "\nselected database successfully!\n";
}
}
return True;
}
function select_from_db($query, $retry=True){
if(!$this->is_connected()){
$result = $this->connect();
echo " 45 : $result\n";
if(!$result)
return $result;
}
echo " executing query \n";
$result = mysql_query($query, $this->db_handle);
if(!$result){
if(stristr(mysql_error(), 'MySQL server has gone away') === False){
$this->error_msg = "Unable to execute query ".mysql_error();
}
else{
if($retry){
$this->db_handle = NULL;
$result = $this->connect_wait(30,5);
return $this->select_from_db($query, False);
}
}
}
echo mysql_error();
echo " returning result $result query \n";
return $result;
}
function insert_to_db($query){
$result = $this->select_from_db($query);
if(!$result)
return $result;
if(stripos($query, 'insert into') !== False){
return mysql_insert_id($this->db_handle);
}
return $result;
}
function is_connected(){
if(is_null($this->db_handle))
return False;
return True;
}
function connect_wait($seconds_to_wait=30, $no_iterations=-1){
$result = $this->connect();
for($counter = 0; ($counter < $no_iterations) && !$result; $counter++){
echo "** $counter \n";
echo "\n$result waiting\n";
sleep($seconds_to_wait);
$result = $this->connect();
echo "\n$result\n";
}
return $result;
}
function disconnect() {
if(!is_null($this->db_handle)){
mysql_close($this->db_handle);
$this->db_handle = NULL;
}
}
function get_error() {
return $this->error_msg;
}
function __destruct() {
$this->disconnect();
}
}
// Connection to database machine
$db_host = 'localhost';
$db_user = 'root1';
#$db_pswd = 'rTpswd$567';
$db_pswd = '';
$db_name = 'test';
$db_table = 'user_login_info';
$db_obj = new database($db_host, $db_user, $db_pswd, $db_name);
if($db_obj->connect()){
echo "Connected";
sleep(20);
echo "Querying";
$query = "select * from $db_table";
$result = $db_obj->select_from_db($query);
if(!$result){
echo mysql_error();
die($db_obj->get_error());
}
while($row = mysql_fetch_assoc($result)){
echo "{$row['user_login_name']} {$row['user_password']}\n";
}
$db_obj->disconnect();
}
?>

Answer 1

PDO is a good library, you don't have to write your own !
You can add a class https://gist.github.com/extraordinaire/4135119 and use it to automatically reconnect when the database is away.