How to Correctly Echo a MySQL Time Difference in PHP?

Echoing a Time Difference from a MySQL Response in PHP

In PHP, you can use the mysql_query() function to execute SQL queries against a MySQL database. However, when you try to echo() the result of a query that returns a time difference, you may encounter the error message "Resource id #6."

Understanding the Error

The error "Resource id #6" indicates that the echo() statement is attempting to print a resource handle instead of the actual data. A resource handle is a unique identifier assigned to the result set by the MySQL server.

Solution

To display the time difference correctly, you need to use a fetch function to retrieve the actual data from the result set. There are several fetch functions available, including mysql_fetch_row(), mysql_fetch_array(), and mysql_fetch_assoc().

Here's an example that uses the mysql_fetch_assoc() function:

$result = mysql_query(sprintf("SELECT TIMEDIFF(NOW(), '%s') as time_delta", $row['fecha']));
if ($result) {
  $data = mysql_fetch_assoc($result);
  echo $data['time_delta'];
}

Note:

The mysql_* functions are deprecated and should not be used in new projects. Instead, use the PDO_MySQL or mysqli extensions.

Improved Example Using PDO

$pdo = new PDO('mysql:host=localhost;dbname=database_name', 'username', 'password');
$stmt = $pdo->prepare("SELECT TIMEDIFF(NOW(), :fecha) as time_delta");
$stmt->bindParam(':fecha', $row['fecha'], PDO::PARAM_STR);
$stmt->execute();
$data = $stmt->fetch(PDO::FETCH_ASSOC);
echo $data['time_delta'];

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