JOIN THREE TABLES IN CODEIGNITER - php

Question

I have three tables
1.article (id,article_title)
2.article_status(id,article_id,stage_id)
3.article_stages(id,stage_name)
Each article have multiple insertion in table 2. I want to fetch the last value which indicate the current stage using join query
article
id article_title
1 article1
2 article2
article_status
id article_id stage_id
1 1 1
2 1 2
3 1 3
4 2 1
article_stages
id stage_name
1 Stage1
2 Stage2
3 Stage3
I need the result like
id article_title stage_name
1 article1 Stage3
2 article2 Stage1
Here is my query
"SELECT `article`.`article_title` as id,`article`.`article_title`,`article_stages`.`stage_name`, MAX(`article_status`.`stage_id`) AS stage_id FROM (`article`)
JOIN `article_status` ON `article_status`.`article_id`=`article`.`id`
JOIN `article_stages` ON `article_stages`.`id` = (SELECT MAX(`stage_id`) FROM `article_status` )
GROUP BY `article_status`.`article_id`"
I tried this
public function getAllArticleforIssue($condition = array())
{
$table1 = 'article';
$table2 = 'article_status';
$table3 ='article_stages';
$this->db->select($table1.'.id as id,'.$table1.'.article_title,'.$table3.'.stage_name');
$this->db->select_max($table2.'.stage_id');
$this->db->from('rsgp_article');
$this->db->join($table2,$table2.'.article_id='.$table1.'.id');
$this->db->join($table3 , $table3.'.id = '.$table2.'.stage_id');
if (count($condition) > 0)
$this->db->where($condition);
$this->db->group_by($table2.".article_id");
$query = $this->db->get();
return $query->result_array();
}

Answer 1

Query Explanation:
Find article_id and current_stage_id ( see subquery groupedTable)
join with article and article_stages table in order to get
description.
SQL:
select article_id, article_title, stage_name
from ( select article_id , max(stage_id) as current_Stage_ID
from article_status
group by article_id ) groupedTable
join article on article.id = groupedTable.article_id
join article_stages on article_stages.id = groupedTable.current_Stage_ID
PHP:
function function_name() {
$sql = "select article_id, article_title, stage_name
from ( select article_id , max(stage_id) as current_Stage_ID
from article_status
group by article_id ) groupedTable join article on article.id = groupedTable.article_id
join article_stages on article_stages.id = groupedTable.current_Stage_ID";
$query = $this -> db -> query($sql);
$result = $query -> result_array();
return $result;
}

Answer 2

Use this query
SELECT a.article_title,s.stage_name
FROM article a
JOIN (
SELECT MAX(stage_id) max_id, article_id
FROM article_status
GROUP BY article_id
) b ON (b.article_id = a.article_id)
JOIN article_stages s ON (s.id = b.max_id)

Answer 3

try this query
$this->db->select('a.id, a.article_title, c.stage_name');
$this->db->from('article a');
$this->db->join('article_status b','b.article_id=a.id','left');
$this->db->join('article_stage c','c.id=b.article_status', 'left');
$this->db->group_by('a.article_name');
$this->db->get()->result_array();

Answer 4

You can use this query
SELECT a.id,a.artcle_title,s.stage_name
FROM article a
JOIN (
SELECT MAX(stage_id) max_id, article_id
FROM article_status
GROUP BY article_id
) b ON (b.article_id = a.id)
JOIN article_stages s ON (s.id = b.max_id)
With ID Column...
modified answer of - #Roshan Dandgavhal