codeigniter mysql stop third consecutive insert - php

Question

I have this codeigniter mysql code to create an appointment:
if ($this->form_validation->run() == TRUE)
{
$data = array(
'startTime' => $startTime ,
'endTime' => $endTime ,
'day' => $date ,
'contact_id' => $this->input->post('InputPatient')
);
$this->db->insert('rdv', $data);
echo 'Appointment Created Successfully.';
}
What I need is - for a specific time like 8pm, I should not have more than 2 appointment created. On third insert with same start time, I should give an error.
Thanks.

Answer 1

Before you do your insert you could do a select to see how many entries there are with the same start time. If there are less than 2 then you can proceed to do your insert.
$this->db->select('count(*) as count')
->from('rdv')
->where('startTime', $startTime)
->where('day', $date);
$query = $this->db->get();
$aResult = $query->row_array();
if($aResult['count'] < 2)
{
//Do your insert
}

Answer 2

Here you go. Before you insert, check if there are already 2 appointments for a specific time and date.
if ($this->form_validation->run() == TRUE)
{
$data = array(
'startTime' => $startTime ,
'endTime' => $endTime ,
'day' => $date ,
'contact_id' => $this->input->post('InputPatient')
);
$isAlreadyTwo = $this->db->from("rdv")
->where(array("startTime" => $startTime, "day" => $day))
->count_all_results() >= 2;
if($isAlreadyTwo)
{
echo "Error!!";
}
else
{
$this->db->insert('rdv', $data);
echo 'Appointment Created Successfully.';
}
}
Hope this helps :)