Query with multiple WHERE and CASE PHP(CodeIgniter) MySQL - php

Question

I'd like to select all period of current term (as now FY80) + 3 period only of last term (FY79) from m_period table
Here's the table m_period looks :
+----+------+-------------+--------+
| id | term | period | status |
+----+------+-------------+--------+
| 1 | FY79 | 79::2020/01 | close |
| 2 | FY79 | 79::2020/02 | close |
| 3 | FY79 | 79::2020/03 | close |
| 4 | FY79 | 79::2020/04 | close |
| 5 | FY79 | 79::2020/05 | close |
| 6 | FY79 | 79::2020/06 | close |
| 7 | FY80 | 80::2020/07 | open |
| 8 | FY80 | 80::2020/08 | open |
| 9 | FY80 | 80::2020/09 | open |
| 10 | FY80 | 80::2020/10 | open |
| 11 | FY80 | 80::2020/11 | open |
| 12 | FY80 | 80::2020/12 | open |
| 13 | FY80 | 80::2021/01 | open |
| 14 | FY80 | 80::2021/02 | open |
| 15 | FY80 | 80::2021/03 | open |
| 16 | FY80 | 80::2021/04 | open |
| 17 | FY80 | 80::2021/05 | open |
| 18 | FY80 | 80::2021/06 | open |
+----+------+-------------+--------+
my php script stuck from here :
<?php
function getPeriod()
{
$prev_term = (int)substr($this->session->userdata('term'),2,2) - 1;
$this->db->select('period');
$this->db->where('term', $this->session->userdata('term'));
$this->db->where('term', $prev_term);
$this->db->order_by('period', 'ASC');
return $this->db->get('m_period')->result_array();
}
I've read CI documentation and couldn't find how to use CASE in codeigniter, or there is another way instead of using CASE ?
can someone help me , how to do this ?
Note : I store current term on session

Answer 1

You can use limit() method.
Then, You have to have two separate functions.
function getPrevPeriod()
{
$prev_term = (int)substr($this->session->userdata('term'),2,2) - 1;
$this->db->select('period');
$this->db->where('term', $prev_term);
$this->db->order_by('period', 'ASC');
$this->db->limit(3);
return $this->db->get('m_period')->result_array();
}
function getCurrentPeriod()
{
$this->db->select('period');
$this->db->where('term', $this->session->userdata('term'));
$this->db->order_by('period', 'ASC');
return $this->db->get('m_period')->result_array();
}
Then you can use array_merge() to combine arrays.
$periods = array_merge($prev, $current);
Edit: With one query
function getPeriod()
{
$prev_term = (int)substr($this->session->userdata('term'),2,2) - 1;
$this->db->select('term','period');
$this->db->or_where_in('term',[$this->session->userdata('term'),$prev_term])
$this->db->order_by('period', 'ASC');
$result = $this->db->get('m_period')->result_array();
$output = [];
$n = 0;
foreach($result as $row){
if($row["term"] == $prev_term){
if($n <= 3){
$output[] = $row;
$n++;
}
}else{
$output[] = $row;
}
}
return $output;
}