如何避免将PHP结果包装到另一个数组中？

Question

The following is the php code:

<?php
session_start();

if(isset($_SESSION["loggedUser"])) {
    generateAndProvideData($_SESSION["loggedUser"]);
} else {
  //error handling
}

function generateAndProvideData($loggedUser) {
    $connection = establishConnectionToDatabase();
    $UserData   = retrieveUserData($connection, $loggedUser);
    echo json_encode($UserData);
}

function retrieveUserData($connection, $loggedUser) {
    return $connection->query("
        SELECT name, vorname, email
        FROM benutzer
        WHERE id = '".$loggedUser."'
    ")->fetchAll(PDO::FETCH_ASSOC);
}

function establishConnectionToDatabase() {
    try {
        $connection = new PDO('mysql:host=localhost;dbname=------------','------','-----');
    } catch(PDOException $e) {
        echo $e->getMessage();
    }
    return $connection;
 }
 ?>

On the scriptside, it was called like this:

function populateUserData() {
  $.post('../include/getUserDataForBenutzerprofil.php', {
    //nothing to transmit
  }).then((data) => {
    data = JSON.parse(data)
    console.log("data from getUserDataForBenutzerprofil.php is ", data)
    //$('#name').val(data.name)
  })
}

Now, as far as I understand php, it creates an array with the names of the columns being the keys to the respective values. However, the array that is returned to the front-end seems to be multidimensional, see the following output:

[{"name":"----","vorname":"-----","email":"[e-mail]"}]

Why is that? And is there any way around it? This way, I always have to address the numerical index "0" first, and then in the second index write out the respective associative key. While this isn't a major issue, it feels rather "unclean", since this is neither necessary nor was it intended.

</div>

Answer 1

According to https://www.w3schools.com/js/js_json_parse.asp

When using the JSON.parse() on a JSON derived from an array, the method will return a JavaScript array, instead of a JavaScript object.

and

As long as the response from the server is written in JSON format, you can parse the string into a JavaScript object.

so try changing your response format to json.

function populateUserData() {
    $.ajax({
        type: "POST",
        url: "../include/getUserDataForBenutzerprofil.php",
        // data: {},
        dataType: "json" //<-- this
    }).then((data) => {
        data = JSON.parse(data)
        console.log("data from getUserDataForBenutzerprofil.php is ", data)    
    })
}

Assuming the response is a valid JSON string of course.