我想从“table1”中删除 (user_id = 5) 的那些行，但我应该检查这些帖子是否“（table2 中的 title = title1）。我使用 Codeigniter，在尝试删除时收到此错误：“除非包含“where”或“like”子句，否则不允许删除。”您能帮我检查一下下面的代码有什么问题吗？

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;
    }

   } 

使用子查询。

example

#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

• 从这里被盗：https://stackoverflow.com/a/16303021/1275832 https://stackoverflow.com/a/16303021/1275832
• 关于子查询：http://www.mysqltutorial.org/mysql-subquery/ http://www.mysqltutorial.org/mysql-subquery/
• 编译选择：https://github.com/NTICompass/CodeIgniter-Subqueries https://github.com/NTICompass/CodeIgniter-Subqueries