How to make has many function in expression engine

Step 1: Make an array

$rel=array();

$rel['exp_incoming_product']['id']='order_id';

$rel['exp_incoming_product']['level']=1;

Notes: 1) Here exp_incoming_product is table name from which you want to make

2) order_id id foreign key of table.

$data=$this->hasMany('exp_incoming_order',$rel,$member_id,'member_id');

Notes: 1)  Here exp_incoming_order is table 

hasMany function

function hasMany($t1,$tables,$id,$t1_id_name)

{

ee()->db->select('*');

ee()->db->from($t1);

ee()->db->order_by('id','desc');

ee()->db->where($t1_id_name,$id);

$query1 = ee()->db->get();

$data=array();

foreach($query1->result_array() as $key_1=>$result) 

{

foreach($result as $key=>$value1) 

{

$data[$key_1][$t1][$key]=$value1;

}

}

foreach($data as $single=>$part) {

foreach($tables as $table=>$value2) {

ee()->db->select('*');

ee()->db->from($table);

ee()->db->where($value2['id'],$part[$t1]['id']);

$query2 = ee()->db->get();

foreach($query2->result_array() as $key2=>$result2) 

{

foreach($result2 as $key3=>$value3) 

{

$data[$single][$table][$key2][$key3]=$value3;

}

}

}

}

return $data; 

}