Ajax POST 请求错误捕获：PHP + jQuery 教程

<?php

//clientHelper.php - Insert data into the database.

if(isset($_POST['sql'])) {
    insertIntoDatabase($_POST['sql']);
}

function insertIntoDatabase($sqlQuery) {
    $ip = "10.10.10.1";
    $port = 3306;
    $username = "candidate";
    $password = "candidate";
    $dbname = "cqtsdb";

    try {
        $connection = new mysqli($ip, $username, $password, $dbname, $port);
        if ($connection->connect_error) {
            throw new Exception("Connection failed: " . $connection->connect_error);
        }
        if ($connection->query($sqlQuery) === FALSE) {
            throw new Exception("Error executing query: " . $connection->error);
        }
        $connection->close();
        echo ""; // 返回空字符串表示成功
    } catch (Exception $e) {
        echo $e->getMessage(); // 返回错误信息
    }

    exit();
}
?>

//JavaScript-function to insert data into a database. The parameter is an SQL-INSERT statement.
function insertIntoDatabase(sqlQuery)
{
    var result;

    $.ajax({
        type: "POST",
        url: "../../general/clientHelper.php",
        data: {sql: sqlQuery},
        async: false,
        error: function(jqXHR, textStatus, errorThrown)
        {
            console.error("AJAX Error:", textStatus, errorThrown);
            if(sqlQuery.split(" ")[0] != "INSERT") console.log("SQL-Query is not an INSERT statement");
            result = false;
        },
        success: function(data)
        {
            if(data == "") {
                result = true; // 后端返回空字符串，表示成功
            } else {
                console.error("PHP Error:", data);
                result = false; // 后端返回错误信息，表示失败
            }
        }
    });

    return result;
}