$ _POST PHP UPDATE错误而不是发送选项

Question

I am trying $_POST an UPDATE to the following mysql table:
Note: there are 3 dropdowns: status, category and access

app_generalData
---------------
app_id
table
status_id
category_id
tags
access_id

Resulting tests with print_r($_POST) and echo(s) 's ensure the form $_POST is working:

Array ( 
        [MAX_FILE_SIZE] => 100000
        [app_id] => 1 
        [title] => Nothing Special 
        [status] => 
        [category] => 
        [tags] => new tag 
        [access] => 
        [update] => Update ) 

Data from the form.

• ID: 1
• Title: Nothing Special
• Status:
• Category:
• Tags: new tag
• Access:

Resulting Error message:

Error querying database for General Data.

Desired result(s):

1. $_POST items updating in the db

Snippet for UPDATE:

// Post the UPDATE to app_generalData
if (isset($_POST['update'])) {
  // print_r($_POST);
  // echo '<br />';

// Connect to the database
$dbc = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);

// Grab the data from the POST

  // General Data
  $app_id = mysqli_real_escape_string($dbc, trim($_POST['app_id']));
  $title = mysqli_real_escape_string($dbc, trim($_POST['title']));
  $status = mysqli_real_escape_string($dbc, trim($_POST['status']));
  $category = mysqli_real_escape_string($dbc, trim($_POST['category']));
  $tags = mysqli_real_escape_string($dbc, trim($_POST['tags']));
  $access = mysqli_real_escape_string($dbc, trim($_POST['access']));

// Confirm success with the user

    echo '<h1>Data from the form.</h1><br />';
    echo 'ID: ' . $app_id .'<br />';
    echo 'Title: ' . $title .'<br />';
    echo 'Status: ' . $status .'<br />';
    echo 'Category: ' . $category .'<br />';
    echo 'Tags: ' . $tags .'<br />';
    echo 'Access: ' . $access .'<br />';

    echo '<br />';

// Write the data to the database
  $query = "UPDATE      app_generalData
            SET         title = $title,
                        status_id = $status,
                        category_id = $category,
                        tags = $tags,
                        access_id = $access
            WHERE       app_id = $app_id
            ";

  mysqli_query($dbc,$query)
        or die('Error querying database for General Data.');

// close MySQL
  mysqli_close($dbc);

  exit();
}
else {
  echo 'Please enter all details below.';
}

Answer 1

Whenever you get mysql_errors i'd suggest the first thing you do if the problem is not found by just looking at the code, is echoing out the query.

What seems to be your problem here is you are not surrounding your string in '' (quotes) like:

$query = "UPDATE      app_generalData
    SET         title = '$title',
                status_id = '$status',
                category_id = '$category',
                tags = '$tags',
                access_id = '$access'
    WHERE       app_id = '$app_id'
    ";