您的 SQL 语法有错误；查看与您的 MariaDB 服务器版本相对应的手册，了解使用 nea 的正确语法

ERRORINSERT INTO new_comp_reg (phno , fullname , address , dept , desc) VALUES ('','','','','') You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'desc) VALUES ('','','' ,'','')' at line 1

PHP

<?php

    $servername = 'mysql.hostinger.in';
    $username = '';
    $password = '';
    $dbname = 'u424351292_icrcm';

    if(isset($_POST['submit']))
    {
        $phone_no = $_POST['phno'];
        $full_name = $_POST['fullname'];
        $location = $_POST['address'];
        $department = $_POST['dept'];
        $description = $_POST['desc'];
    }

        $conn = new mysqli($servername,$username,$password,$dbname);

        if($conn->connect_error)
        {
            die("Connection Failed" . $conn->connect_error);
        }

        $sql = "INSERT INTO new_comp_reg (phno , fullname , address , dept , desc)  VALUES ('$phone_no' , '$full_name' , '$location' , '$department' , '$description')";

        if($conn->query($sql) === TRUE)
        {
            echo "Complaint Registered";
        }
        else
        {
            echo "ERROR".$sql."<br>".$conn->error;
        }

    $conn->close();
    ?>

//错误

ERRORINSERT INTO new_comp_reg (phno , fullname , address , dept , desc) VALUES ('','','','','')您的 SQL 语法有错误；检查与您的 MariaDB 服务器版本相对应的手册，以在第 1 行的 'desc) VALUES ('','','' ,'','')' 附近使用正确的语法

INSERT INTO new_comp_reg (..., `desc`)  VALUES (...)