[RESOLVED] redundant code!

[atmorell]

Hi.

I have created a "Data Access Object" for my Raw_Materials table. However there is a lot of redundant code! This is an example:

/**
* The Raw_Materials Data Access Object
*
* Represents the RawMaterials Data Structure of a Record.
*
* It uses the mysql connection object and functions as a
* container for common and complicated queries.
*
* @access public
*/
class Raw_Materials_dao {
    protected $_connection; // protected so the variable cannot be accessed outside of the class.

public function __construct($connection)
{
    $this->_connection = $connection;
}

public function get($id)
{
$sql = '
SELECT
  `raw_materials`.`raw_material_id`,
  `raw_materials`.`raw_material_name`,
  `raw_materials`.`raw_material_unit`,
  `raw_materials`.`raw_material_price`
FROM
  `raw_materials`
WHERE (`raw_materials`.`raw_material_id` = '.$id.')';
return $this->_connection->query($sql);
}

public function get_all()
{
$sql = '
SELECT
  `raw_materials`.`raw_material_id`,
  `raw_materials`.`raw_material_name`,
  `raw_materials`.`raw_material_unit`,
  `raw_materials`.`raw_material_price`
FROM
  `raw_materials`
';
return $this->_connection->query($sql);
}

public function search($request)
{
$sql = '
SELECT
  `raw_materials`.`raw_material_id`,
  `raw_materials`.`raw_material_name`,
  `raw_materials`.`raw_material_unit`,
  `raw_materials`.`raw_material_price`
FROM
  `raw_materials`
WHERE `raw_material_name` LIKE \'%' . $request->get('search_term') . '%\'';
$result = $this->connection->query($sql);
return $result;
}
}

Is there a simple way that I can remove all the redundant code in the sql select statement? What is best practice to avoid this kind of "problems"?

Best regards.
Asbjørn Morell.

[timus]

Hey

One way would be to define a class variable

Class raw_mat
{
var $sql
...

Then create a function with the same name as the class which will be called every time you create a new instance of the class.

In the new function you can initialise the $this->sql variable to be the same as the get_all function.

In all your other functions you can say

 $new_sql = $this->sql + ' where ....'

As long as you don't change the class variable, it should be ok for running any function.

I'm not sure if this is the best way but it should certainly cut down on the lines of code

Hope this helps

Tim

[bpat1434]

I'd use this class:

<?php

class Raw_Materials_dao
{
	protected $_connection;
	var $sql;

public function __construct($connection)
{
	$this->_connection = $connection;
	initSQL();
}

private function initSQL()
{
	$this->sql = "
		SELECT
		  `raw_materials`.`raw_material_id`,
		  `raw_materials`.`raw_material_name`,
		  `raw_materials`.`raw_material_unit`,
		  `raw_materials`.`raw_material_price` 
	    FROM
		 `raw_materials` ";
}

public function sql_add($clause)
{
	$this->sql .= $clause;
}

public function runQuery()
{
	return $this->_connection->($this->sql);
}
}

?>

And then call it like so:

$dao = new Raw_Materials_dao($connection);

$dao->sql_add("WHERE `raw_materials`.`raw_material_id` = '$id'");
$dao->runQuery();

[atmorell]

Hi.

Thank you.

Best regards.
Asbjørn Morell.