这个问题已经在这里有了答案：            >            How to get MySQLi error information in different environments? / mysqli_fetch_assoc() expects parameter 1 to be mysqli_result                                    1个
我的以下代码在我的本地主机服务器上工作.当我将其托管到实际服务器时,尽管建立了连接,但查询无法正常工作.
输出是

“result problem”

<?php
include_once 'db_connect.php'; 

class test{
    public function test1(){
        $db_connect = new db_connect();
        $con = $db_connect->connect();
        if(!$con){
            echo "connection fail";
        }else{
            $sql = "select * from tbl_admin where name='abc' ";
            $query = mysqli_query($con,$sql);
            if(!$query){
                    echo "result problem";
                }else{
                        $result = mysqli_fetch_array($query);
                        echo $result['ad_tp'];
                    }
        }
    }
}

$t = new test();
$t->test1();

解决方法:

更换

echo "result problem";

与

printf("Errormessage: %s\n", mysqli_error($link));

这将使您确切了解为什么不执行查询.