如何自动回显所有列值

For example I have an attributes table and I can add infinite attributes. I do that with ALTER TABLE when I add a new column and UPDATE when I insert the value of the attribute. All these columns must be shown in a table. However I am having dificulties with showing the newly added column value.

Here is how a static column value echo would look like:

public function showAllUsers(){
    $x = $this->getAllUsers();
    foreach ($x as $data) {
      echo '<tr>';
        echo '<th>'. $data['id'].'</th>';
        echo '<td>'.$data['user'].'</td>';
        echo '<td>'.$data['email'].'</td>';
        echo '<td>'.$data['age'].'</td>';
      echo '</tr>';
    }
  } 

It echoes the values of the database that I have specified. But I need a loop that will echo any newly added value so the static echo method above won't work.

This is what I have come up with so far:

public function showAllUsers(){
    $x = $this->getAllUsers();
    foreach ($x as $data) {

      echo '<tr>';
        print_r( '<th>'. $data.'</th>');
      echo '</tr>';
    }
  }

And it just shows a Notice: Array to string conversion and echoes one tag with value of 0. How do i echo all of the content from one row?

Try this:

public function showAllUsers()
{
    $x = $this->getAllUsers();
    echo '<tr>';
    foreach (array_keys($x[0]) as $field) {
        echo '<th>'. $field.'</th>';
    }
    echo '</tr>';
    foreach ($x as $data) {
        echo '<tr>';
        foreach ($data as $val) {
            echo '<td>'. $val.'</td>';
        }
        echo '</tr>';
    }
} 

You can implode the $data array with the html tags.
Implode takes all array values and joins them with the "glue" and makes it a string.

public function showAllUsers(){
    $x = $this->getAllUsers();
    foreach($x as $data){
        echo "<tr>";
        echo "<th>" . implode("</th><th>", $data) . "</th>";
        echo "</tr>";
    }
}