您可以按照以下操作:

$this->db->where('id', $post['identifier']);
$this->db->set('votes', 'votes+1', FALSE);
$this->db->update('users');

之所以有效，是因为第三个(可选)FALSE 参数告诉 CodeIgniter 不要用反引号 (') 保护生成的查询.这意味着生成的 SQL 将是:

UPDATE users SET votes= votes + 1 WHERE id='44'

如果您注意到，从 '(votes+1)' 中删除了反引号，这会产生将 votes 属性增加 1 的预期效果.

The reason this works is because the third (optional) FALSE parameter tells CodeIgniter not to protect the generated query with backticks ('). This means that the generated SQL will be:

UPDATE users SET votes= votes + 1 WHERE id= '44'

If you notice, the backticks are removed from '(votes+1)', which produces the desired effect of incrementing the votes attribute by 1.