more classes

[l0ve2hat3]

how do i access mssql_value in db_manager class, if i am in pca_inventory class???

 

 

<?php

class db_manager{

    public $dbname="gnglatt";
    public $host="MARS\PCAMERICA";
    public $port="1092";
    public $user="demo";
    public $password="demo";
    public $connection;

   function _connect(){
        $this->connection=mssql_connect($this->host,$this->user,$this->password);
        mssql_select_db($this->dbname,$this->connection);
   }

   public function check_connect(){
        if(!$this->connection)$this->_connect();
   }
   public function query($query){
            $this->check_connect();
           $qresult=mssql_query($query) or Die($query);
           return $qresult;
   }


  public function mssql_value($table,$field,$id,$idfield="id"){
  	$sql='SELECT ['.$field.'] FROM ['.$table.'] WHERE ['.$idfield.']="'.$id.'"';
  	$value=mssql_result($this->query($sql),0,$field);
  	return $value;
  }
}





class pca_inventory{
    public function get_price($item_number){
        return db_manager::mssql_value('Inventory','Price',$item_number,'ItemNum');
    }

}


$item = new pca_inventory;
echo $item->get_price('LUNCHSPEC');


?>

[l0ve2hat3]

**how do i access db_manager::mssql_value(), if i am in pca_inventory class???

[rhodesa]

your concept of classes is still off. i've sat her trying to type out an explanation, but can't seem to come up with something. there is something about classes where it is so hard to explain to someone else. did you go through that tutorial I posted in your other thread?

[Maq]

You can use extends if you want to invoke methods from another class.

 

class pca_inventory extends db_manager{

[l0ve2hat3]

yeah i went through the tutorial...

 

i know i could use extends but i thought u might be able to do this..

 

class pca_inventory{
    public $db=new db_manager;
    public function get_price($item_number){
        return $db->mssql_value('Inventory','Price',$item_number,'ItemNum');
    }

}

 

no go...

 

rhodesa- any way to try to tell me what i am doing wrong with the concept??

 

 

[l0ve2hat3]

well this works, but y cant i make $db public?? so confused

 

class pca_inventory{

    public function get_price($item_number){
        $db=new db_manager;
        return $db->mssql_value('Inventory','Price',$item_number,'ItemNum');
    }

}

[KevinM1]

well this works, but y cant i make $db public?? so confused

 

class pca_inventory{

    public function get_price($item_number){
        $db=new db_manager;
        return $db->mssql_value('Inventory','Price',$item_number,'ItemNum');
    }

}

 

Why would you want it to be public?  In the vast, vast majority of cases, class properties should be private.

[l0ve2hat3]

i guess your right... but im bothered now... what am i missing about my concept of classes??

[KevinM1]

i guess your right... but im bothered now... what am i missing about my concept of classes??

 

Well, it's hard to tell from looking at a couple of code snippets....

 

Let's start with what you do know, and work from there.

[gizmola]

As you've seen there is no problem instantiating an object of class A inside of class B.  You simply do this type of work inside a method.  You can't declare a class variable and instantiate an object in the declaration, but that's simply syntax.