在codeigniter中交叉加入？

Question

我正在尝试这个

$this->db->join('tableTwo as b','','CROSS');
$result = $this->db->get('tableOne as a')->result(); 

一些解决方案？

Answer 1

codeigniter中的交叉连接解决方​​案：

$this->db->join('tableTwo as b','true');
$result = $this->db->get('tableOne as a')->result(); 

Answer 2

你应该这样使用它：

$this->db->join('tableTwo as b','true');
$result = $this->db->get('tableOne as a')->result(); 

Answer 3

在codeigniter 3中，您可以通过以下方式添加交叉联接查询构建器

$this->db->join('tableTwo as b','1=1');                    //true relation
$result = $this->db->get('tableOne as a')->result(); 

或通过从method或get methods中传递数组

$result = $this->db->get(['tableOne as a','tableTwo as b'])->result(); 

或

$result = $this->db->from(['tableOne as a','tableTwo as b'])
get()->result();     //by this method you can add as many table you want to join

或通过在get方法中将一个表从另一个表中传入

$result = $this->db->from('tableOne as a')
get('tableTwo as b')->result(); 

Answer 4

对于那些来看 Codeigniter 4 答案的人：

// tableOne is defined in the model
$this->model->join('tableTwo', 'column_x= column_y', 'cross');

第一个参数是表名，下一个参数是连接条件，第三个参数是连接类型。

所以如果你有一个这样的 SQL 语句：

cross join producto_resumen_color on prre_id = prco_prre_id

你会这样做：

->join('producto_resumen_color','prre_id = prco_prre_id', 'cross')

您可以在 CI 的用户指南中找到更多信息。

https://codeigniter.com/user_guide/database/query_builder.html?highlight=join#join

join($table, $cond[, $type = ''[, $escape = NULL]])

Parameters: 

    $table (string) – Table name to join
    $cond (string) – The JOIN ON condition
    $type (string) – The JOIN type
    $escape (bool) – Whether to escape values and identifiers