Codeigniter无法使用join方法从数据库表中删除行 [英] Codeigniter cannot delete rows from database table using join method

问题描述

我想从'table1'删除（user_id = 5），但我应该检查这些帖子'（title = title1在table2）。我使用Codeigniter和我得到这个错误，同时尝试删除：'删除是不允许的，除非它们包含一个where或like子句。你能请我帮助我检查下面的代码是什么错误。

I want to delete from ‘table1’ those rows where (user_id = 5) but I should check if those posts’ (title = title1 in table2). I use Codeigniter and I get this error while trying to delete: ‘Deletes are not allowed unless they contain a "where" or "like" clause.’ Could you please help me to check what is wrong with my code below.

table1：

table2：

public function delete($title, $user_id){ 

    $this->db->select('table1.*');
    $this->db->from('table1','table2');   
    $this->db->where('table1.user_id', $user_id); 
    $this->db->where('table2.title', $title);
    $this->db->join('table2','table1.post_id=table2.post_id');

     $query = $this->db->get();   

        if ($query && $query->num_rows() > 0) {

    $this->db->delete('table1.*');
    $this->db->from('table1','table2');   
    $this->db->where('table1.user_id', $user_id); 
    $this->db->where('table2.title', $title);
    $this->db->join('table2','table1.post_id=table2.post_id');
    return true;
            } 
    else {
    return false;
    }

   } 

推荐答案

使用子查询。

#Create where clause
$this->db->select('id');
$this->db->from('table2');
$this->db->where('table2.title', $title);
$where_clause = $this->db->get_compiled_select();

#Create main query
$this->db->where('table1.user_id', $user_id); 
$this->db->where("`id` NOT IN ($where_clause)", NULL, FALSE);
$this->db->delete('table1'); 

参考

• 从此处被盗： http://stackoverflow.com/a/16303021/1275832


• 关于子查询： http://www.mysqltutorial.org/mysql-subquery/


• 编译选择： https://github.com/NTICompass/ CodeIgniter-Subqueries



References

• stolen from here: http://stackoverflow.com/a/16303021/1275832
• about subqueries: http://www.mysqltutorial.org/mysql-subquery/
• compiled select: https://github.com/NTICompass/CodeIgniter-Subqueries

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