Start Order by data from table that is found in another table - sql

Question

My question may be not easy to explain but I am going to do my best.
I have 3 tables :
medicine
patient
patient_medicine
the third table contains 3 columns :
auto increment (id)
medicine_id
patient_id
I make a query that display all data in medicine table and if there is a patient id found in patient_medicine table I check it and those that are not found are not checked.
A- controller
public function showPatientMedicine()
{
$data['patient_id']=$this->input->post('patient_id');
$data['medicine'] = $this->model_admin->medicine();
$this->load->view('admin/show-Patient-Medicine',$data);
}
B- VIEW
<table>
<thead>
<tr>
<th>List</th><th></th>
</tr>
</thead>
<tbody>
<?php
foreach($medicine as $row){
$patient_med=$this->db->select('medicine_id')
->where('patient_id',$patient_id)
->where('medicine_id',$row->id)
->get('patient_medicine')->row('medicine_id');
if($row->id==$patient_med){
$checked="checked";
} else {
$checked="";
}
?>
<tr>
<td>
</td>
<td>
<input type='checkbox' value="<?=$row->id?>" <?=$checked?> />
</td>
</tr>
<?php
}
?>
</tbody>
</table>
THIS QUERY SHOWS ME ALL MEDICINES AND CHECK THE MEDICINES THAT ARE FOUND IN PATIENT_MEDICINE TABLE
MY QUESTION IS :
HOW CAN I SHOW ALL MEDICINES THAT ARE CHECKED IN THE FIRST POSITION OR HOW TO ORDER BY CHECKED CHECKBOX ?
THANK YOU IN ADVANCE.

Answer 1

Try this,
SELECT * FROM `medicine` as a left join (select medicine_id,patient_id from patient_medicine where patient_id = 2) as b on a.id = b.medicine_id
Put the above query in your controller, it will automatically sort the result based on patient id, if patient details found. it will return null for all other details in rows except medicine details.
So you can just
<?php foreach($medicine as $row){ ?>
<input type='checkbox' value="<?=$row->id?>" <?php echo !is_null($row->patient_id)?'checked':''; ?> />
<?php } ?>