Add alter to classes file

[Peuplarchie]

Good day to you all,

            I new in php MySQL classes and I have found a nice model. (See code 1 later)

 

I would like to add to it but I'm not sure how, can somebody help me, any help is good to learn !

 

Code 1 (Model Class)

<?php
# Name: Database.class.php
# File Description: MySQL Class to allow easy and clean access to common mysql commands
# Author: ricocheting
# Web: http://www.ricocheting.com/
# Update: 2010-05-08
# Version: 3.1.3
# Copyright 2003 ricocheting.com


/*
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/


//require("config.inc.php");
//$db = Database::obtain(DB_SERVER, DB_USER, DB_PASS, DB_DATABASE);

//$db = Database::obtain();


###################################################################################################
###################################################################################################
###################################################################################################
class Database{

// debug flag for showing error messages
public	$debug = true;

// Store the single instance of Database
private static $instance;

private	$server   = ""; //database server
private	$user     = ""; //database login name
private	$pass     = ""; //database login password
private	$database = ""; //database name

private	$error = "";

#######################
//number of rows affected by SQL query
public	$affected_rows = 0;

private	$link_id = 0;
private	$query_id = 0;


#-#############################################
# desc: constructor
private function __construct($server=null, $user=null, $pass=null, $database=null){
// error catching if not passed in
if($server==null || $user==null || $pass==null || $database==null){
	$this->oops("Database information must be passed in when the object is first created.");
}

$this->server=$server;
$this->user=$user;
$this->pass=$pass;
$this->database=$database;
}#-#constructor()


#-#############################################
# desc: singleton declaration
public static function obtain($server=null, $user=null, $pass=null, $database=null){
if (!self::$instance){ 
	self::$instance = new Database($server, $user, $pass, $database); 
} 

return self::$instance; 
}#-#obtain()


#-#############################################
# desc: connect and select database using vars above
# Param: $new_link can force connect() to open a new link, even if mysql_connect() was called before with the same parameters
public function connect($new_link=false){
$this->link_id=@mysql_connect($this->server,$this->user,$this->pass,$new_link);

if (!$this->link_id){//open failed
	$this->oops("Could not connect to server: <b>$this->server</b>.");
	}

if(!@mysql_select_db($this->database, $this->link_id)){//no database
	$this->oops("Could not open database: <b>$this->database</b>.");
	}

// unset the data so it can't be dumped
$this->server='';
$this->user='';
$this->pass='';
$this->database='';
}#-#connect()



#-#############################################
# desc: close the connection
public function close(){
if(!@mysql_close($this->link_id)){
	$this->oops("Connection close failed.");
}
}#-#close()


#-#############################################
# Desc: escapes characters to be mysql ready
# Param: string
# returns: string
public function escape($string){
if(get_magic_quotes_runtime()) $string = stripslashes($string);
return @mysql_real_escape_string($string,$this->link_id);
}#-#escape()


#-#############################################
# Desc: executes SQL query to an open connection
# Param: (MySQL query) to execute
# returns: (query_id) for fetching results etc
public function query($sql){
// do query
$this->query_id = @mysql_query($sql, $this->link_id);

if (!$this->query_id){
	$this->oops("<b>MySQL Query fail:</b> $sql");
	return 0;
}

$this->affected_rows = @mysql_affected_rows($this->link_id);

return $this->query_id;
}#-#query()


#-#############################################
# desc: does a query, fetches the first row only, frees resultset
# param: (MySQL query) the query to run on server
# returns: array of fetched results
public function query_first($query_string){
$query_id = $this->query($query_string);
$out = $this->fetch($query_id);
$this->free_result($query_id);
return $out;
}#-#query_first()






#-#############################################
# desc: fetches and returns results one line at a time
# param: query_id for mysql run. if none specified, last used
# return: (array) fetched record(s)
public function fetch($query_id=-1){
// retrieve row
if ($query_id!=-1){
	$this->query_id=$query_id;
}

if (isset($this->query_id)){
	$record = @mysql_fetch_assoc($this->query_id);
}else{
	$this->oops("Invalid query_id: <b>$this->query_id</b>. Records could not be fetched.");
}

return $record;
}#-#fetch()


#-#############################################
# desc: returns all the results (not one row)
# param: (MySQL query) the query to run on server
# returns: assoc array of ALL fetched results
public function fetch_array($sql){
$query_id = $this->query($sql);
$out = array();

while ($row = $this->fetch($query_id)){
	$out[] = $row;
}

$this->free_result($query_id);
return $out;
}#-#fetch_array()


#-#############################################
# desc: does an update query with an array
# param: table, assoc array with data (not escaped), where condition (optional. if none given, all records updated)
# returns: (query_id) for fetching results etc
public function update($table, $data, $where='1'){
$q="UPDATE `$table` SET ";

foreach($data as $key=>$val){
	if(strtolower($val)=='null') $q.= "`$key` = NULL, ";
	elseif(strtolower($val)=='now()') $q.= "`$key` = NOW(), ";
        elseif(preg_match("/^increment\((\-?\d+)\)$/i",$val,$m)) $q.= "`$key` = `$key` + $m[1], "; 
	else $q.= "`$key`='".$this->escape($val)."', ";
}

$q = rtrim($q, ', ') . ' WHERE '.$where.';';

return $this->query($q);
}#-#update()




#-#############################################
# desc: Add column 
# param: 
# returns: 
public function alter($table, $data){
$q="ALTER `$table` ADD COLUMN ";

foreach($data as $key=>$val){
	if(strtolower($val)=='null') $q.= "`$key` = NULL, ";
	elseif(strtolower($val)=='now()') $q.= "`$key` = NOW(), ";
        elseif(preg_match("/^increment\((\-?\d+)\)$/i",$val,$m)) $q.= "`$key` = `$key` + $m[1], "; 
	else $q.= "`$key`='".$this->escape($val)."', ";
}

$q = rtrim($q, ', ') . ' WHERE '.$where.';';

return $this->query($q);
}#-#alter()




#-#############################################
# desc: Duplicate row
# param: 
# returns: 


#-#duplicate()




#-#############################################
# desc: does an insert query with an array
# param: table, assoc array with data (not escaped)
# returns: id of inserted record, false if error
public function insert($table, $data){
$q="INSERT INTO `$table` ";
$v=''; $n='';

foreach($data as $key=>$val){
	$n.="`$key`, ";
	if(strtolower($val)=='null') $v.="NULL, ";
	elseif(strtolower($val)=='now()') $v.="NOW(), ";
	else $v.= "'".$this->escape($val)."', ";
}

$q .= "(". rtrim($n, ', ') .") VALUES (". rtrim($v, ', ') .");";

if($this->query($q)){
	return mysql_insert_id($this->link_id);
}
else return false;

}#-#insert()



#-#############################################
# desc: frees the resultset
# param: query_id for mysql run. if none specified, last used
private function free_result($query_id=-1){
if ($query_id!=-1){
	$this->query_id=$query_id;
}
if($this->query_id!=0 && !@mysql_free_result($this->query_id)){
	$this->oops("Result ID: <b>$this->query_id</b> could not be freed.");
}
}#-#free_result()


#-#############################################
# desc: throw an error message
# param: [optional] any custom error to display
private function oops($msg=''){
if(!empty($this->link_id)){
	$this->error = mysql_error($this->link_id);
}
else{
	$this->error = mysql_error();
	$msg="<b>WARNING:</b> No link_id found. Likely not be connected to database.<br />$msg";
}

// if no debug, done here
if(!$this->debug) return;
?>
	<table align="center" border="1" cellspacing="0" style="background:white;color:black;width:80%;">
	<tr><th colspan=2>Database Error</th></tr>
	<tr><td align="right" valign="top">Message:</td><td><?php echo $msg; ?></td></tr>
	<?php if(!empty($this->error)) echo '<tr><td align="right" valign="top" nowrap>MySQL Error:</td><td>'.$this->error.'</td></tr>'; ?>
	<tr><td align="right">Date:</td><td><?php echo date("l, F j, Y \a\\t g:i:s A"); ?></td></tr>
	<?php if(!empty($_SERVER['REQUEST_URI'])) echo '<tr><td align="right">Script:</td><td><a href="'.$_SERVER['REQUEST_URI'].'">'.$_SERVER['REQUEST_URI'].'</a></td></tr>'; ?>
	<?php if(!empty($_SERVER['HTTP_REFERER'])) echo '<tr><td align="right">Referer:</td><td><a href="'.$_SERVER['HTTP_REFERER'].'">'.$_SERVER['HTTP_REFERER'].'</a></td></tr>'; ?>
	</table>
<?php
}#-#oops()




}//CLASS Database
###################################################################################################












?>

 

 

 

Now I'm trying to add a function that would let me add column.

 

Please look at function alter in the code1 and if you can lead me tomy understanding.

 

 

 

 

 

Thanks!