Codeigniter内部联接不起作用

Question

我想与Codeigniter进行内部连接，我尝试了很多，但没有成功。

用于内部联接的MySQL代码，

SELECT * FROM shop INNER JOIN city ON city.city_id = shop.city_id WHERE city.city_name = 'Bangalore'

上面的sql查询在phpmyadmin中运行正常。 在codeigniter中转换此代码时，它不起作用。

Codeigniter代码是，

$this->db->select('*');
$this->db->from('shop');
$this->db->join('city', 'city.city_id = shop.city_id');
$query = $this->db->where('city', array('city.city_name' => 'Bangalore'));

if($query->num_rows() > 0) {
    return $result = $query->result_array();
}
else {
    return 0;
}

哪里出了问题。 是codeigniter的初学者。

Answer 1

您的查询应该运作良好：

$this->db->select('*');
$this->db->from('shop');
$this->db->join('city', 'city.city_id = shop.city_id');
//$this->db->where('city', array('city.city_name' => 'Bangalore'));
$this->db->where('city.city_name', 'Bangalore');
$query = $this->db->get();

Answer 2

尝试这个：

$query = $this->db->select('*')
          ->from('shop')
          ->join('city', 'city.city_id = shop.city_id', 'inner')
          ->where('city.city_name', 'Bangalore');
          ->get();

Answer 3

您错过了从db get()数据的机会，

更改为

$query = $this->db->where('city', array('city.city_name' => 'Bangalore'));

这个

$this->db->where('city', array('city.city_name' => 'Bangalore'));
$query = $this->db->get();// add this line.

不需要from()您可以使用get()并将表名传递给它，就像这样。

$this->db->select('*');
//$this->db->from('shop');   <-- no need of this line
$this->db->join('city', 'city.city_id = shop.city_id');
$this->db->where('city', array('city.city_name' => 'Bangalore'));
$query = $this->db->get("shop");//<-- give table name here only.