PHP can't update SQL - php

Question

I'm using a php part in my site, where I have a textarea that get a text from a database. The user can edit this text and after he finish press the save button, and using UPDATE I will change the text in the database.
Here is my code:
<?php
$con=mysqli_connect("localhost","userdb","codedb","projectdb");
mysqli_set_charset($con, 'utf8');
// Check connection
if (mysqli_connect_errno()) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$myQueryfac="SELECT text FROM main WHERE id=1";
$result = mysqli_query($con,$myQueryfac);
while($row = mysqli_fetch_array($result)) {
$t1=$row['text'];
}
$form="<form action='adminindex.php' method='post'>
<textarea name='area1' maxlength='1500' cols='50' rows='10'>$t1</textarea>
<input type='submit' name='enter' value='Save'>
</form>";
if($_POST['enter']) {
$t1=$_POST['area1'];
mysqli_query($con,"UPDATE main SET text='$t1' WHERE id='1'");
}
echo $form;
mysqli_close($con);
?>
My problem is in the UPDATE query it seems like it ignores $t1 and nothing change in database. But if I put something random in there, "RANDOM TEXT", change it successful.

Answer 1

This is how you do it:
test.php
// DB Connect
$con=mysqli_connect("localhost","userdb","codedb","projectdb");
mysqli_set_charset($con, 'utf8');
if (mysqli_connect_errno()) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
// Handle POST
if (count($_POST))
{
// Save In DB
mysqli_query($con, sprintf("UPDATE main SET `text`='%s' WHERE id=%d",
mysqli_real_escape_string($con, $_POST['area1']),
1)); // id
// Success
echo "<p>Data updated.</p>";
}
// Load Existing Data
$myQueryfac="SELECT `text` FROM main WHERE id=1";
$result = mysqli_query($con, $myQueryfac);
$row = mysqli_fetch_array($result);
// Display Form
echo "<form action='test.php' method='post'>
<textarea name='area1' maxlength='1500' cols='50' rows='10'>". $row['text'] ."</textarea>
<input type='submit' name='enter' value='Save'>
</form>";
// DB Close
mysqli_close($con);
?>
What I've changed
Moved the post hander up (above the select statement), so that if an update occurs, the form will show the latest updated data
Your update query was treating the id as string, I formatted it to be a digit (%d)
Removed the while loop, you don't need it as it is a single row being returned
added sql-injection prevention (using sprintf and mysqli_real_escape_string)
added backticks `` around the db field name text (wasn't sure if this is a reserved word, because it's one of the sql data types)

Answer 2

Try to do
mysqli_query($con,"UPDATE main SET text='$t1' WHERE id=1");
Instead
mysqli_query($con,"UPDATE main SET text='$t1' WHERE id='1'");
It could be the WHERE condition that bring your problems

Answer 3

You are checking the $_POST array for a value not existing. enter is your submit button and will not send a value.
Try this:
if($_POST['area1']) {
$t1=$_POST['area1'];
mysqli_query($con,"UPDATE main SET text='$t1' WHERE id='1'");
}