How to UPDATE only filled input with a submit button? - php

Question

PROBLEM: I got a problem updating my input into sql using PHP, the PHP updates all empty values into sql which I don't want to.
ACHIEVEMENT: So I hope to achieve when user submit their data either empty or filled then PHP might be able to pickup and update only filled data into my sql. I tried using input with value=">php echo here<" but it won't work with textarea, so I couldn't find any solution since I'm new to PHP and SQL. Tried to find similar posts but I couldn't make them work like I wanted to :(
<?php include 'config/sqlconnect.php'; ?>
<form method="post" action"config/sqlconnect.php">
</p>MainPage info</p>
<input type="text" name="mainPageInfo"/>
<br>
</p>MiddlePage info</p>
<textarea name="middlePageInfo"></textarea>
<br>
</p>Container info</p>
<input type="text" name="containerInfo"/>
<br>
</p>Content</p>
<input type="text" name="content"/>
<br>
</p>Second content</p>
<input type="text" name="secondContent"/>
<input type="submit" name="submit" class="btn-block"/>
<br>
</form>
in PHP script
<?php
$servername = "localhost";
$username = "root";
$password = "pass";
$dbname = "pagesDb";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
mysqli_set_charset($conn,"utf8");
$sql = "SELECT * FROM myPages";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
$mainPageInfo = $row['mainPageInfo'];
$middlePageInfo = $row['middlePageInfo'];
$containerInfo = $row['containerInfo'];
$content = $row['content'];
$secondContent = $row['secondContent'];
}
} else {
echo "0 results";
}
if (isset($_POST['submit'])) {
$mainPageInfo = $_POST['mainPageInfo'];
$middlePageInfo = $_POST['middlePageInfo'];
$containerInfo = $_POST['containerInfo'];
$content = $_POST['content'];
$secondContent = $_POST['secondContent'];
$sql = "UPDATE myPages SET mainPageInfo='$mainPageInfo',
middlePageInfo='$middlePageInfo',
containerInfo='$containerInfo',
content='$content',
secondContent='$secondContent'
WHERE id=0";
if ($conn->query($sql) === TRUE) {
echo "Record updated successfully";
} else {
echo "Error updating record: " . $conn->error;
}
}
$conn->close();
?>
Second Attempts: It doesn't update my data somehow... please help I tried more than 8 hours with no results :(
if (isset($_POST['submit'])) {
foreach($_POST as $name => $value) {
$sql = "UPDATE myPages SET $name = '$value' WHERE id=1";
}
if ($conn->query($sql) === TRUE) {
echo "Record updated successfully";
} else {
echo "Error updating record: " . $conn->error;
}
}
Help would be appreciated, thanks everyone!

Answer 1

Using your Second Attempt as a starting point.
The problem with just using the POST array without being specific is that, in this example you are going to try an update a column on the database called submit i.e. your submit button. Later there may be data on the page that belongs in 2 or more tables.
So create an controlling array containing all the field names from the form that you want to process onto your table.
$db_fields = array('mainPageInfo', 'middlePageInfo', 'containerInfo',
'content', 'secondContent');
$sql = ''; // will hold the query we build dynamically
// was this a user sending data
if ( $_SERVER['REQUEST_METHOD' == 'POST' ) {
foreach($db_fields as $fieldname) {
if ( ! empty($_POST[$fieldname] ) {
$sql .= "$fieldname = '{$_POST[$fieldname]}', ";
}
}
}
$sql = rtrim($sql, ','); // remove the trailing comma
$sql = "UPDATE myPages SET $sql WHERE id=1";
if ($conn->query($sql) === TRUE) {
echo "Record updated successfully";
} else {
echo "Error updating record: " . $conn->error;
}