Yii one model for multiple tables - php

Question

I have Yii application and two tables with same structure tbl and tbl_history:
Now want to create model so it will select table by parameter I send when calling model. For example:
MyModel::model('tbl')->find();
//and
MyModel::model('tbl_history')->find();
Find related article with solution in Yii forum. Made same changes and finally got this in MyModel:
private $tableName = 'tbl'; // <=default value
private static $_models=array();
private $_md;
public static function model($tableName = false, $className=__CLASS__)
{
if($tableName === null) $className=null; // this string will save internal CActiveRecord functionality
if(!$tableName)
return parent::model($className);
if(isset(self::$_models[$tableName.$className]))
return self::$_models[$tableName.$className];
else
{
$model=self::$_models[$tableName.$className]=new $className(null);
$model->tableName = $tableName;
$model->_md=new CActiveRecordMetaData($model);
$model->attachBehaviors($model->behaviors());
return $model;
}
}
Now when I make:
echo MyModel::model('tbl_history')->tableName(); // Output: tbl_history
It returns right value, but:
MyModel::model('tbl_history')->find();
still returns value for tbl.
Added:
public function __construct($id=null,$scenario=null){
var_dump($id);
echo '<br/>';
parent::__construct($scenario);
}
and got:
string(tbl_history)
string(tbl_history)
NULL
It means Yii makes call to model from other place but don't know from where and how to prevent it.
Also It makes 2 calls to model, is it too bad for performance?

Answer 1

It looks like the CActiveRecord::getMetaData() method needs to be overridden to achieve what you are looking for.
<?php
class TestActiveRecord extends CActiveRecord
{
private $tableName = 'tbl'; // <=default value
private static $_models=array();
private $_md;
public function __construct($scenario='insert', $tableName = null)
{
if($this->tableName === 'tbl' && $tableName !== null)
$this->tableName = $tableName;
parent::__construct($scenario);
}
public static function model($tableName = false, $className=__CLASS__)
{
if($tableName === null) $className=null; // this string will save internal CActiveRecord functionality
if(!$tableName)
return parent::model($className);
if(isset(self::$_models[$tableName.$className]))
return self::$_models[$tableName.$className];
else
{
$model=self::$_models[$tableName.$className]=new $className(null);
$model->tableName = $tableName;
$model->_md=new CActiveRecordMetaData($model);
$model->attachBehaviors($model->behaviors());
return $model;
}
}
public function tableName()
{
return $this->tableName;
}
/**
* Returns the meta-data for this AR
* #return CActiveRecordMetaData the meta for this AR class.
*/
public function getMetaData()
{
if($this->_md!==null)
return $this->_md;
else
return $this->_md=static::model($this->tableName())->_md;
}
public function refreshMetaData()
{
$finder=static::model($this->tableName());
$finder->_md=new CActiveRecordMetaData($finder);
if($this!==$finder)
$this->_md=$finder->_md;
}
}

Answer 2

Maybe it's easier to make MyModelHistory which extends MyModel and overrides only one method - tableName().

Answer 3

I recommend implementing single table inheritance. In order to do this you will need to combine your tables with a flag or type column that states whether or not this is a history record. I've pasted a few links at the bottom so you can see how this is implemented in Yii and listed some of the benefits below.
Benefits:
You won't need to duplicate code commonly used between the models
Changes to this table will only need to be executed once.
Changes to the parent model will only need to be made once.
Code becomes generally more maintainable and readable.
You seperate the code that belongs specifically to tbl and tbl_history
http://www.yiiframework.com/wiki/198/single-table-inheritance/
http://en.wikipedia.org/wiki/Single_Table_Inheritance

Answer 4

I created a solution for performing this exact action a couple of months ago. This is a completely dynamic solution, you just pass the table name like you are looking for to the model. That solution was originally designed to work with the same database structure across multiple databases, but it was trivial to adapt it to work in the same database. The documentation for that is here. I'd recommend reading over it as it has more details about CDynamicRecord
It's easy to adapt to work with multiple tables. You can download the adaptation as a gist from github.
Usage
1) Download the Gist and drop it into ext, save as CDynamicRecordSDB.php
2) Create Your model in Model, and setup up as follows:
Basically, you want to extend CDynamicRecord, and override your model() and tableName() so they are compliant with CDyanmicRecord.
<?php
Yii::import('ext.CDynamicRecordSDB');
class Test extends CDynamicRecordSDB
{
public static function model($dbConnectionString = 0, $className=__CLASS__)
{
return parent::model($dbConnectionString, $className);
}
public function tableName()
{
return $this->dbConnectionString;
}
[... Do everything else after this ...]
}
3) Setup your model as you normally would.
Usage
The usage is identical to CActiveRecord, and you can perform all actions. No surprises. Just a couple examples below.
$data = Test::model('tbl')->findAll();
$data2 = new Test('tbl');
$data2->findAll();
foreach ($data as $row)
print_r($row->attributes);
$data = Test::model('tbl_history')->findAll();
foreach ($data as $row)
print_r($row->attributes);
Limitations
The only limitation with doing this is you have to modify how relations work. IF you plan on accessing a related model (Bar), and you have no intention on calling Bar by itself. Then Bar should extend CActiveRecord, and in Foo you can define normal relations. Yii magically carries over the CDbConnectionString across the instances for you.
OTHERWISE, if you intend to access models in the same database, but also want to retain the ability to call them by themselves, then Bar should extend CDynamicModel, and Foo should have a getter defined as follows.
public function getBar()
{
return Bar::model($this->$dbConnectionString);
}

Answer 5

A small way but work for me for any number of table
public static $dynamic_table_name="main_table";
public static function setDynamicTable($param)
{
self::$dynamic_table_name=self::$dynamic_table_name.$param;
}
/**
* #return string the associated database table name
*/
public function tableName($param='')
{
self::setDynamicTable($param);
return self::$dynamic_table_name;
}
// to use it like
ModelName::model()->tableName('_one');
ModelName::model()->tableName('_two');
ModelName::model()->tableName('_three');