PHP连接数据库后，增加字段内容会导致出现502

Question

PHP代码如下：

$serve = 'localhost:3306';
$username = 'adminroot';
$password = '123698745';
$dbname = '研究室';
$link = mysqli_connect($serve,$username,$password,$dbname) or die('数据库连接失败');
mysqli_set_charset($link,'UTF-8'); // 设置数据库字符集

$topicsResult = mysqli_query($link,'select intime,content from topics');

mysqli_query($link,"INSERT INTO topics (content) VALUES('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa');");

echo print_r(mysqli_fetch_all($topicsResult)) ; // 字段多了就显示502 Bad Gateway
//echo json_encode($data);
?>

MySQL数据库如下

CREATE TABLE `topics` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `intime` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  `content` TEXT,
  `url` VARCHAR(254) DEFAULT NULL,
  PRIMARY KEY (`id`)
)

mysqli_query($link,"INSERT INTO topics (content) VALUES('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa');");运行七八次之后，也就是添加了七八行之后，就会报502错误，推测问题应该出在mysqli_fetch_all($topicsResult)，因为502出现之后数据库字段还是照常可以增加，请问大佬们有没有解决方案

Answer 1

https://www.cnblogs.com/doseoer/p/5972002.html