Mysql 代码点火器连接中的问题

我在CI活动记录表单中有此查询

$this->db->select('companies.*,comp_permissions.user_id');
$this->db->from('companies');
$this->db->join('comp_permissions', 'companies.id = comp_permissions.comp_id');
$query = $this->db->get();

它生成如下查询

SELECT `hs_companies`.*, `hs_comp_permissions`.`user_id`
FROM (`hs_companies`)
INNER JOIN `hs_comp_permissions` ON `hs_companies`.`id` = `hs_comp_permissions`.`comp_id`

但我最初的疑问是

Select cb.*,cbp.user_id
from hs_companies cb
INNER JOIN hs_comp_permissions cbp ON 
(cb.id = cbp.comp_id AND cbp.status=2 AND cbp.user_id = 72)

那么现在我如何在连接函数中放置多个列呢

更新

当我试着这样做的时候

$this->db->select('companies.*,comp_permissions.user_id');
$this->db->from('companies');
$this->db->join('comp_permissions', '(companieas.id = comp_permissions.comp_id AND comp_permissions.status = 2 AND comp_permissions.user_id = 72)','inner');
$this->db->get()->result();

它生成以下结果

SELECT `hs_companies`.*, `hs_comp_permissions`.`user_id` 
FROM (`hs_companies`) 
INNER JOIN `hs_comp_permissions` ON 
(`hs_companies`.`id` = `hs_comp_permissions`.`comp_id` AND comp_permissions.status = 2 AND comp_permissions.user_id = 72)

---

它不添加

hs\ucode>my db prefix
您可以这样做：

$this->db->select('companies.*,comp_permissions.user_id');
$this->db->from('companies');
$this->db->join('comp_permissions', '(companies.id = comp_permissions.comp_id 
                                     AND cbp.status=2 
                                     AND cbp.user_id = 72)');
$query = $this->db->get();

你能在
的哪里设置它吗

$this->db->select('companies.*,comp_permissions.user_id');
$this->db->from('companies');
$this->db->join('comp_permissions', 'companies.id = comp_permissions.comp_id');
$this->db->where('comp_permissions.status', '2');
$this->db->where('comp_permissions.user_id', '72');
$query = $this->db->get();

或者，您可以手动设置db前缀：

$this->db->join('comp_permissions', '(companies.id = comp_permissions.comp_id 
                                     AND hs_comp_permissions.status=2 
                                     AND hs_comp_permissions.user_id = 72)');

我确实喜欢这样做，但它遗漏了我的db prefixcan，我们可以在
where
子句周围放置
（
）？试试看，它有什么用？