codeigniter中发生数据库错误.

Jul*_*rts 3 php captcha codeigniter

这个错误是什么?我如何解决它?
我使用codeigniter.

A Database Error Occurred
Error Number: 1048

Column 'captcha_time' cannot be null

INSERT INTO `captcha` (`captcha_time`, `ip_address`, `word`) VALUES (NULL, '31.57.141.7', NULL)

Filename: /home/324/public_html/123/models/login_model.php

Line Number: 79
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第79行:

function create_captcha()
    {
    $vals = array(
        'img_path'   => './captcha/',
        'img_url'    => 'captcha/',
    );
$cap = create_captcha($vals);
    $data = array(
    'captcha_time'  => $cap['time'],
    'ip_address'    => $this->input->ip_address(),
    'word'   => $cap['word']
    );
    $query = $this->db->insert_string('captcha', $data);
    $this->db->query($query); // this line 79
    }
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mat*_*jkd 6

您收到此错误,因为文件夹"/ captcha"不在您的服务器上或设置了错误的权限.

如果图像路径不存在,或者不可写,则create_captcha()函数返回false,请查看验证码助手.