不了解mysqli_fetch_array

Question

So i guess i don't understand this i am a very newbie to coding in general. I have searched and can't find a good enogh explanation to get it to work in my situatation. I need to fill a table from a fetch command then update each result with an input of information into a new column. Here is the code i have:

This fills the table:

    echo "<table border='1'>
    <tr>
    <th>Envelope</th>
    <th>Budget</th>
    <th>Amount</th>
    </tr>";

    while($row = mysqli_fetch_array($result)) {

    echo "<tr>";
    echo "<td>" . $row['envelopename'] . "</td>";
    echo "<td>" . $row['envelopebudget'] . "</td>";
    ?><td><input type="text" name="budgetamount"></td><?php;
    echo "</tr>";
    }

    echo "</table>";
?>  
    <input type="submit">

And this writes the input for budgetname into the column budgetname:

$paycheckname = mysqli_real_escape_string($con, $_POST['paycheckname']);
$budgetamount = mysqli_real_escape_string($con, $_POST['budgetamount']);
$envelopename = mysqli_real_escape_string($con, $_POST['envelopename']);
}

$sql="UPDATE envelopes SET $paycheckname='$budgetamount' WHERE envelopename ='$envelopename'";

if (!mysqli_query($con,$sql)) {
  die('Error: ' . mysqli_error($con));
}

Right now it just doesn't write anything. I have used echo var_dump($envelopename)."<br>"; and echo var_dump($budgetamount)."<br>"; var_dump($envelopename)."<br>"; and echo var_dump($budgetamount)."<br>"; to try and see what it is doing but $envelopename is always blank. Thanks for any help you can provide.

Answer 1

only <input> , <textarea> , <select> and <button> are submitted to the server in a form

If you want to re-submit some static values create some hidden inputs

while($row = mysqli_fetch_array($result)) {

echo "<input type='hidden' value='$row[envelopename]' name='envelopename'/>";
echo "<input type='hidden' value='$row[envelopebudget]' name='envelopebudget'/>";
echo "<tr>";
echo "<td>" . $row['envelopename'] . "</td>";
echo "<td>" . $row['envelopebudget'] . "</td>";
?><td><input type="text" name="budgetamount"></td><?php;
echo "</tr>";
}

echo "</table>";

But your next issue will be that you're creating the elements in a loop so you'll have multiple inputs with the same name

<tr>
    <input type='hidden' value='envName1' name='envelopename'/>
    <input type='hidden' value='envBudget1' name='envelopename'/>
    <td>envName1</td>
    <td>envBudget1</td>
    <td><input type="text" name="budgetamount"></td>
</tr>
<tr>
    <input type='hidden' value='envName2' name='envelopename'/>
    <input type='hidden' value='envBudget2' name='envelopename'/>
    <td>envName2</td>
    <td>envBudget2</td>
    <td><input type="text" name="budgetamount"></td>
</tr>

so you must submit as an array

while($row = mysqli_fetch_array($result)) {

echo "<input type='hidden' value='$row[envelopename]' name='envelopename[]'/>";
echo "<input type='hidden' value='$row[envelopebudget]' name='envelopebudget[]'/>";
echo "<tr>";
echo "<td>" . $row['envelopename'] . "</td>";
echo "<td>" . $row['envelopebudget'] . "</td>";
?><td><input type="text" name="budgetamount[]"></td><?php;
echo "</tr>";
}

echo "</table>";

and at the server end process as an array

 foreach ($_POST['budgetamount'] as $budgetamount){
       echo $budgetamount. '<br>';
  }

Answer 2

suppose the form rendered looks like this:

<tr>
    <input type='hidden' value='envName1' name='envelopename[]'/>
    <input type='hidden' value='envBudget1' name='envelopebudget[]'/>
    <td>envName1</td>
    <td>envBudget1</td>
    <td><input type="text" name="budgetamount[]"></td>
</tr>
<tr>
    <input type='hidden' value='envName2' name='envelopename[]'/>
    <input type='hidden' value='envBudget2' name='envelopebudget[]'/>
    <td>envName2</td>
    <td>envBudget2</td>
    <td><input type="text" name="budgetamount[]"></td>
</tr>
<tr>
    <input type='hidden' value='envName3' name='envelopename[]'/>
    <input type='hidden' value='envBudget3' name='envelopebudget[]'/>
    <td>envName3</td>
    <td>envBudget3</td>
    <td><input type="text" name="budgetamount[]"></td>
</tr>

when the user hits submit the $_POST that arrives at newpaycheck.php will look like:

$_POST
['envelopename']{
   [0]=>'envName1',
   [1]=>'envName2',
   [2]=>'envName3'
},['envelopebudget']{
   [0]=>'envBudget1',
   [1]=>'envBudget2',
   [2]=>'envBudget3'
},['budgetamount']{
   [0]=>'someValueEnteredByUser',
   [1]=>'anotherValueEnteredByUser',
   [2]=>'yetAnotherValueEnteredByUser'
}

so you can do something like this:

foreach ($_POST['envelopename'] as $envelopename){
   $arrayIndex = array_search($envelopename,$_POST['envelopename']);
   $envelopebudget = $_POST['envelopebudget'][$arrayIndex];
   $budgetamount= $_POST['budgetamount'][$arrayIndex];

   $paycheckname = mysqli_real_escape_string($con, $envelopebudget);
   $budgetamount = mysqli_real_escape_string($con,$budgetamount);
   $envelopename = mysqli_real_escape_string($con,$envelopename);

   $sql="UPDATE envelopes SET $paycheckname='$budgetamount' WHERE envelopename ='$envelopename'";

   if (!mysqli_query($con,$sql)) {
       die('Error: ' . mysqli_error($con));
    }

}