如何将 sql union 转换为 codeigniter 方式

Question

如何使用 PHP CodeIgniter 框架进行 UNION 查询我在执行此查询时遇到错误

Every derived table must have its own alias

型号

function search_blog($title){
$query = $this->db->query("SELECT * FROM (
                SELECT id,section,title,img,year,lastupdateon AS ondate,'moves' AS dept,STATUS FROM movies
                UNION
                SELECT ID,section,Title,img,year,lastupdateon AS ondate,'kid' AS dept,STATUS FROM kids
                UNION
                SELECT ID,views,Title,img,version AS year,ondate,'software' AS dept,STATUS FROM soft
                UNION
                SELECT ID,section,Title,img,'PC Game' AS year,ondate,'game' AS dept,STATUS FROM games
                UNION
                SELECT ID,season,Title,img,type AS year,lastupdatedon AS ondate,'tvshow' AS dept,STATUS FROM tvshows
                )");
        $this->db->like('Title', $title , 'after');
        $this->db->order_by('ondate', 'DESC');
        $this->db->limit(10);
        return $this->db->get($query)->result();
    }

如何修改

Answer 1

你可以简单地通过为每个表添加查询并使用这样的联合来连接它们

$this->db->select('ID,section,title,img,year,lastupdateon AS ondate,`moves` AS dept,STATUS');
$this->db->from('movies');
$query1 = $this->db->get_compiled_select();

$this->db->select('ID,section,title,img,year,lastupdateon AS ondate,`kid` AS dept,STATUS');
$this->db->from('kids');
$query2 = $this->db->get_compiled_select();

$this->db->select('ID,views,title,img,version AS year,ondate,`software` AS dept,STATUS');
$this->db->from('soft');
$query3 = $this->db->get_compiled_select();


$this->db->select('ID,section,title,img,'PC Game' AS year,ondate,`game` AS dept,STATUS');
$this->db->from('games');
$query4 = $this->db->get_compiled_select();

$this->db->select('ID,season,title,img,type AS year,lastupdatedon AS ondate,`tvshow` AS dept,STATUS');
$this->db->from('tvshows');
$query5 = $this->db->get_compiled_select();

$this->db->like('title', $title , 'after');
$this->db->order_by('ondate', 'DESC');
$this->db->limit(10);


$query = $this->db->query($query1 . ' UNION ' . $query2. ' UNION ' . $query3. ' UNION ' . $query4. ' UNION ' . $query5);

return $this->db->get($query)->result();