是否可以使用Javascript更新SQL数据库中的数据？

Question

I'm starting to learn some of SQL with javascript and i want to put my variable ("Val_Points from javascript") into a table ("Usuarios") of a user (ex : Robert). It's this posible via Javascript or there are some other methods ?

 var Val_Points = 0; /* Variable */ $('.btn').click(function() { Val_Points += 5; /* value +5 */ /* Update individual SQL Data var UpdateSQL = dbConn.executeUpdate('UPDATE Usuarios SET Points="$Val_Points" WHERE Username="$_SESSION[username]"'); */ $('#exp_bar').val(Val_Points); }); 

 <?php session_start(); require 'connect.php'; $username_session = $_SESSION['username']; /* "Robert" Session */ $query = "SELECT * FROM `Usuarios` WHERE usuario='$username_session'"; $result = mysqli_query($connection, $query); ?> <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <p>Points</p> <progress id ="exp_bar" value="0" max="100"></progress><br> <button class="btn">+1</button> 

Also i was seeing a script that simplifly this https://hiddentao.github.io/squel/ Maybe could be more readable in scripting with this. Any help?

EDIT

I tried to do all of this with php via $_SESSION

 <?php session_start(); require 'connect.php'; $username_session = $_SESSION['username']; $query = "SELECT * FROM `Usuarios` WHERE username='$username_session'"; $result = mysqli_query($connection, $query); if(empty($_SESSION['Val_Points'])){ $Val_Points_Session = $_SESSION['Val_Points'] = 0; } echo "<form action='' method='POST'> <progress id ='exp_bar' value='".$_SESSION['Val_Points']++."' max='100'></progress> <input class='btn' type='submit' value='Increase val' /> </form>"; echo $_SESSION['Val_Points']; /* Show current variable */ $Update_SQL = "UPDATE Usuarios SET Points='$Val_Points_Session' WHERE username='$username_session'"; ?> 

But it doesn't update the table, the table keeps with the same value

Username Points
Robert 0

Answer 1

Is it possible to insert data with Javascript to an SQL database

Simple answer is no. Not just with Javascript.

For understanding this you need to know the difference between client-side and server-side .

Client-side

Operations that are performed by the client. The operations are made by the computer/software of the user. This also means the client can modify the data how ever he want.

Server-side

Operations that are performed by the server. The operations are made on an server and uses just the information that is send by the client. After the data is recived the client can not modify it.

Your database is on the server-side its on your server. The client has no direct acces to this database, so you need to send the data from the client-side to the server-side . This can be done with javascript .

So how to do this.

In your case you wanna combine Javascript (client) with PHP (server). Via PHP we insert the data to your SQL database.

Example

Javascript / Jquery(!)

We going to use $.ajax() . This is an function out of the jQuery framework and makes an request to your server.

$('.btn').click(function() {
    var request = $.ajax({
        url: "phpfile.php",
        data: { label: "value" },
        method: "POST"
    });

    request.done(function() {
        // Do something after its done.
    });
 });

PHP

<?php

    if ($_SERVER['REQUEST_METHOD'] === 'POST') {
      // do your database stuff.
      // the data you send from the client is in the $_POST array.
      // for example $_POST['label']
    }

?>

Answer 2

"Standard" approach

foo.php is the site which contains a button and includes a script:

<button id="update-btn">update</button>
...
<script src="foo.js"></script>

foo.js adds the on click handler:

$('#update-btn').click(function() {
    $.ajax({
        'url': 'fooHandler.php',
        'method': 'POST',
        'data': {'sid': ..., 'action': 'update', 'value': ...}
        /* 'success': function(data) { ... } */
        /* 'error': function ... */
    });
});

fooHandler.php handles requests to the server from the clients:

<?php
  if (isset($_POST['sid'], $_POST['action'])) {
    /* TODO check if valid session */
    if ($_POST['action'] == 'update') {
      /* check if the rest is in order */
      if (isset($_POST['value'] and is_numeric($_POST['value'])) {
        /* TODO execute query */
      }
    } elseif ($_POST['action'] == ...) {
      ...
    }
  }
?>