[lord mazdak]

Varför skulle en DB abstraction layers konstruktor behöva ändring om classen är skriven som min
Ge mig 1 passande senario då jag skulle behöva ändra på den.
Hela Klassen :

<?php
/*--------------------------------------------
|	file = db/mysql.php
|	description : A database class
|	--------------
|	copyright = (C) 2005 The Magicasoft Group
|	email = [email protected]
*-------------------------------------------*/

class DB
{
	var $host; // The hostname
	var $user; // The username
	var $password; // The password
	var $database; // The database
	var $conn = array('server' => 0, 'database' => 0); // Database and Server connection recource
	var $query = array(); // The exsisting querys
	var $currMethod; // The last result
	var $lang_struct = array('text' => 'TEXT',
	'primkey const' => 'NOT NULL auto_increment',
	'primkey' => 'PRIMARY KEY (#2)',
	'spec prim' => '',
	'primkey dt int' => 'INTEGER(#1)');

	function DB($host,$user,$password,$database) // PHP4 class constructor
	{
 // populate the properties thats needed for connection
 $this->host = $host;
 $this->user = $user;
 $this->password = $password;
 $this->database = $database;
	}

	function __construct($host,$user,$password,$database) // PHP5 class constructor
	{
 // populate the properties thats needed for connection
 $this->host = $host;
 $this->user = $user;
 $this->password = $password;
 $this->database = $database;
	}

	function connect($errormode = 'print') // connect to the database
	{
 if($errormode === 'return')
 {
 	$ext_test = ( function_exists('mysql_connect') ? '' : -1);
 	if($ext_test === -1) return -1;
 	$this->conn['server'] = @mysql_connect($this->host,$this->user,$this->password);
 	return (@mysql_select_db($this->database,$this->conn['server']) ? 1 : 0);
 }

 $this->conn['server'] = mysql_connect($this->host,$this->user,$this->password) or $this->error('Can\'t connect to the server');
 $this->conn['database'] = mysql_select_db($this->database,$this->conn['server']) or $this->error('Can\'t connect to the database');
	}

	function close() // close the database connection
	{
 $this->query = NULL;
 mysql_close($this->conn['server']);
	}

	function query($query,$queryname,$overwrite = 'no') // run a query
	{
 if(!isset($this->query[$queryname]) || $overwrite === 'yes') // make sure there is no chance of unwanted conlicts with queries
 {
 	$this->query[$queryname] = $this->currMethod = mysql_query($query,$this->conn['server']) or $this->error($queryname.' invalid query');
 	return $this->currMethod;
 }
 else $this->error('Can\t overwrite query : '.$queryname); // display error
	}

	function fetch_row($queryname) // fetch a row as an array
	{
 $this->currMethod = mysql_fetch_row($this->query[$queryname]);
 return $this->currMethod;
	}

	function fetch_assoc($queryname,$load = 'yes') // fetch a row as an hash
	{
 if($load === 'no') // check if query is outside $this->query
 {
 	$this->currMethod = mysql_fetch_assoc($queryname);
 	return $this->currMethod;
 }
 else
 {
 	$this->currMethod = mysql_fetch_assoc($this->query[$queryname]);
 	return $this->currMethod;
 }
	}

	function num_rows($queryname) // get the number of rows in a query
	{
 if(mysql_num_rows($this->query[$queryname]))
 {
 	$this->currMethod = (string)mysql_num_rows($this->query[$queryname]) or $this->error('Can\'t get the number of rows from query : '.$queryname);
 	return (int)$this->currMethod;
 }
	}

	function showcolumns($table,$keep = 'no') // show the columns of a table
	{
 $this->query("SHOW COLUMNS FROM $table",'showcolumns_'.$table);
 while($col = $this->fetch_assoc('showcolumns_'.$table))
 {
 	extract($col);
 	$columns[$Field]['name'] = $Field;
 	$Type = explode('(',$Type);
 	$columns[$Field]['type'] = $Type[0];
 	$columns[$Field]['maxlength'] = str_replace(')','',$Type[1]);
 }
 $this->currMethod = $columns;
 
 if($keep === 'no') unset($this->query['showcolumns_'.$table]);
 
 return $this->currMethod;
	}

	function ALTER_TABLE($table,$action,$column,$type = '',$length = '',$newcolumn = '') // add,edit,delete columns from a table
	{
 if($action === 'add') // handle adding columns
 {
 	$this->query("ALTER TABLE {$table} ADD COLUMN {$column} {$type}{$length} NOT NULL",'alter-table-add_sql');
 }
 elseif($action === 'edit') // handle editing columns
 {
 	$this->query("ALTER TABLE {$table} RENAME {$column} TO {$newcolumn}",'alter-table-edit_sql');
 	$this->query("ALTER TABLE {$table} MODIFY {$newcolumn} {$type}{$length} NOT NULL",'alter-table-edit_sql','yes');
 }
 elseif($action === 'delete') // handle deleting columns
 {
 	$this->query("ALTER TABLE {$table} DROP COLUMN {$column}",'alter-table-delete_sql');
 }
	}

	function lang() // get a sql language structure
	{
 $num_args = func_num_args(); // number of arguments
 if($num_args === 0) trigger_error('Invalid argument count for function : lang, the function need atleast 1 argument',E_USER_ERROR); // function can't be void
 elseif($num_args === 1) return $this->lang_struct[func_get_arg(0)]; // if only 1 argument the return the language stucture
 else // handle language structures with arguments/variables
 {
 	$code = $this->lang_struct[func_get_arg(0)];
 	
 	for($i = 1; $i < $num_args; $i++)
 	{
  ${$i} = func_get_arg($i);
  $code = preg_replace('/#'.$i.'/',$$i,$code);
 	}
 	return $code;
 }
	}

	function error($msg) // display the last error and terminate
	{
 $error = mysql_error();
 $errorcode = mysql_errno();

 $message = 'Database error in Magicasoft BBman 2:'.$msg.'
 Database Error:'.error.'
 Error Code: '.$errorcode.'
 Date: '.date('F j, Y h:i A').'
 Script: '.$_SERVER['REQUEST_URI'];
 echo'
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
 <html>
 <head>
 <title>Magicasoft BBman 2 Database Error</title>
 <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
 <style type="text/css">
 body, p
 { 
 	font-family: verdana,arial,helvetica,sans-serif;
 	font-size: 11px;
 }
 </style>
 </head>
 <body>
 <blockquote><p><strong>Fatal error caused by fault in database.</strong><br/>
 You may try this action again by pressing <a href="javascript:window.location=window.location;">refresh</a>.</p>
 <p>We apologise for any inconvenience.</p>
 <form action="null"><textarea rows="10" cols="55">'.$message.'</textarea></form>
 </blockquote>
 </body>
 </html>';
 die;
	}
}
?>