我无法使用
order by rand() limit 5
之后
['user_id']
有办法做到这一点吗，请帮忙。
$sqlstate = "select * from questions, users where users.category_id=questions.category_id and users.user_id=".$_SESSION['user_id'] order by rand() limit 5;
您只需要修复字符串和连接。
$sqlstate = "select * from questions, users where users.category_id=questions.category_id and users.user_id=".$_SESSION['user_id']." order by rand() limit 5";
或者，由于您似乎在使用PHP，您可以只使用双引号中的变量：
$sqlstate = "select * from questions, users where users.category_id=questions.category_id and users.user_id=$_SESSION['user_id'] order by rand() limit 5";