check if database row is empty

Question

I have a database wich looks like this:

+----------+----------+---------+----------+
| bogie_id | train_id | axle_nr | bogie_nr |
+----------+----------+---------+----------+
|        1 |        1 |       1 |          |
|        2 |        1 |       2 |          |
|        3 |        1 |       3 |          |
|        4 |        1 |       4 |          |
+----------+----------+---------+----------+

As you can see the "bogie_nr" rows are empty.
No i wana make an if statement, wich checks if the rows are empty or filled in. What i currently have:

    <div id="bogiebox">
        <tr> 
            <?php    
                $x = 1;  
                foreach($show_axle as $bogiebox){ ?>
                <input type='hidden' name='bogie_id[<?php echo $bogiebox['bogie_id']?>]' value='<?php echo $bogiebox['bogie_id']?>'>
                <td>
                    <?php 
                        if($bogiebox['bogie_nr'] == ''){
                    ?>
                        <input type='checkbox' id="bogie_axle_fields" value="<?= $x ?>" name='bogie_nr[<?php echo $bogiebox['bogie_id']?>]'></td>
                    <?php
                        }
                        else{ 
                    ?>
                        <input type='checkbox' id="bogie_axle_fields" checked disabled></td><?php } }
            ?>
        </tr>
    </div>

And then the if statement:

    <?php
        if(isset($_POST['y'])){
            $bogiefilledin = false;
                if(!empty($_POST['bogie_nr'])) {
                    echo "everything is full?";
                }
                else {
                    echo "Fill in some more fields";
                }
        }
    ?>

It is not done yet! but what it should do is:
We check a checkbox or 2. press the send button, and the database inserts the number 1 for the 2 selected bogies. Then the page refeshes and all the checkboxes should have a value of 2. And on the next insert they will insert the value 2. and so on and so on.

But, what i would like = if i filled in my database like this:

+----------+----------+---------+----------+
| bogie_id | train_id | axle_nr | bogie_nr |
+----------+----------+---------+----------+
|        1 |        1 |       1 |     1    |
|        2 |        1 |       2 |     1    |
|        3 |        1 |       3 |     2    |
|        4 |        1 |       4 |          |
+----------+----------+---------+----------+

I would like to see the else statement (Fill in some more fields). because the 4th axle is not in a bogie yet.

Right now the if else statement shows me: when i select 1 and press submit it says: "everything is full!" . and when i select nothing it says: "Fill in some more fields.". However it does not insert anything yet, so it should always say: Fill in some more fields!.

How do i do this??

Answer 1

try changing if(!empty($_POST['bogie_nr'])) to this if($_POST['bogie_nr']!='')