I have a mysqli error in my library file {ERROR :: mysqli_fetch_assoc() expects parameter 1 to be mysqli_result, null given}

Question

我的库文件有一个mysqli错误ERROR :: mysqli_fetch_assoc() expects parameter 1 to be mysqli_result, null given谁能帮我解决一下

我的安装程序文件：

public function __construct()
    {
        $CI = &get_instance();
        $CI->load->database();
        if ($CI->db->database == '') {
            header('location:install/');
        } else {
            //query from installer tbl
            $installer = mysqli_query('SELECT installer_flag FROM installer');
            $item = mysqli_fetch_assoc($installer);
            $flag = $item['installer_flag'];
            // if installer_flag = 0
            if ($flag == 0) {
                // make it 1
                mysqli_query('UPDATE installer SET installer_flag=1 WHERE id=1');
                if (is_dir('install')) {
                    header('location:install/success.php');
                }
            }
            //run this code
            //else nothing
        }
    }

错误：mysqli_fetch_assoc() 期望参数 1 为 mysqli_result，给定为空

Answer 1

1st : mysqli_query 需要两个参数第一个参数是 connection object 第二个参数是 sql query

示例：

mysqli_query($connection_object,$query);

编程硝石：

$result = $this->db->query('SELECT installer_flag FROM installer')->result();
print_r($result);

Answer 2

如果您正在使用 CI 然后使用其内置函数来获取结果

$query = $this->db->query('SELECT installer_flag FROM installer');
foreach ($query->result_array() as $row)
{
   echo $row['title'];
}

I have a mysqli error in my library file {ERROR :: mysqli_fetch_assoc() expects parameter 1 to be mysqli_result, null given}

I have a mysqli error in my library file {ERROR :: mysqli_fetch_assoc() expects parameter 1 to be mysqli_result, null given}

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