update mysql row with html form and php - php

Question

I've been looking through many threads on here without finding a solution to my problem.
I've created a form that is supposed to show content of a database in input boxes, and when i change the content, it should be updated in the database.
No errors, nothing gets changed.
<?php
$con=mysqli_connect("localhost","root","","frontpage");
// Check connection
if (mysqli_connect_errno()){
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$result = mysqli_query($con,"SELECT * FROM frontpage_left_links")
or die("Error: ".mysqli_error($con));
while($row = mysqli_fetch_array($result)){
echo '<form action="" method="post">';
echo '<div style="float:left">';
echo '<table border="1" bordercolor="#000000">';
echo '<tr>';
echo '<td>link</td>';
echo '<td><input type="text" name="linkid" value="'.$row['link'].'"></td>';
echo '</tr>';
echo '<tr>';
echo '<td>img</td>';
echo '<td><input type="text" name="imgid" value="'.$row['img'].'"></td>';
echo '</tr>';
echo '<tr>';
echo '<td>tekst</td>';
echo '<td><input type="text" name="imgid" value="'.$row['name'].'"></td>';
echo '</tr>';
echo '<tr>';
echo '<td><input type="submit" id="update" name="gem" value="Gem"</td></td>';
echo '<td><input type="hidden" name="id" value="'.$row['id'].'"></td>';
echo '</tr>';
echo '</table></div>';
echo '<div style="float:left"><center><img src="img/'.$row['img'].'"><br />'.$row['name'].'</center></div>';
echo '</form><br /><br /><br /><br /><br /><br /><br /><br />';
}
if(isset($_POST['update'])){
$id = $_POST['id'];
$link = $_POST['linkid'];
$img = $_POST['imgid'];
$name = $_POST['nameid'];
$sql = mysqli_query("UPDATE frontpage_left_links SET link = '$link', img = '$img', name = '$name' WHERE id = '$id'");
$retval = mysqli_query( $sql, $con );
if(! $retval ){
die('Could not update data: ' . mysql_error());
}
echo "Updated data successfully\n";
}
mysqli_close($con);
?>
The form show the database content fine, but nothing happens when changed.
I appreciate any help I can get.
This is what it looks like now.
<?php
$con=mysqli_connect("localhost","root","","frontpage");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
if(isset($_POST['gem']))
{
$id = $_POST['id'];
$link = $_POST['linkid'];
$img = $_POST['imgid'];
$name = $_POST['nameid'];
$sql = mysqli_query("UPDATE frontpage_left_links SET link = '$link', img = '$img', name = '$name' WHERE id = '$id'");
$retval = mysqli_query( $con, $sql );
if(! $retval )
{
die('Could not update data: ' . mysql_error());
}
echo "Updated data successfully\n";
}
$result = mysqli_query($con,"SELECT * FROM frontpage_left_links")
or die("Error: ".mysqli_error($con));
while($row = mysqli_fetch_array($result))
{
echo '<form action="" method="post">';
echo '<div style="float:left">';
echo '<table border="1" bordercolor="#000000">';
echo '<tr>';
echo '<td>link</td>';
echo '<td><input type="text" name="linkid" value="'.$row['link'].'"></td>';
echo '</tr>';
echo '<tr>';
echo '<td>img</td>';
echo '<td><input type="text" name="imgid" value="'.$row['img'].'"></td>';
echo '</tr>';
echo '<tr>';
echo '<td>tekst</td>';
echo '<td><input type="text" name="nameid" value="'.$row['name'].'"></td>';
echo '</tr>';
echo '<tr>';
echo '<td><input type="submit" id="update" name="gem" value="Gem"</td></td>';
echo '<td><input type="hidden" name="id" value="'.$row['id'].'"></td>';
echo '</tr>';
echo '</table></div>';
echo '<div style="float:left"><center><img src="img/'.$row['img'].'"><br />'.$row['name'].'</center></div>';
echo '</form><br /><br /><br /><br /><br /><br /><br /><br />';
}
mysqli_close($con);
?>
Now i get this error.
Warning: mysqli_query() expects at least 2 parameters, 1 given in /Applications/XAMPP/xamppfiles/htdocs/page/admin.php on line 17
Warning: mysqli_query(): Empty query in /Applications/XAMPP/xamppfiles/htdocs/page/admin.php on line 19
Could not update data:

Answer 1

Because your udate is at the end of the page put it above the rest.
And also change isset($_POST['update'] to isset($_POST['gem']
<?php
$con=mysqli_connect("localhost","root","","frontpage");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
if(isset($_POST['gem']))
{
$id = $_POST['id'];
$link = $_POST['linkid'];
$img = $_POST['imgid'];
$name = $_POST['nameid'];
$sql = "UPDATE frontpage_left_links SET link = '$link', img = '$img', name = '$name' WHERE id = '$id'";
$retval = mysqli_query($con,$sql );
if(! $retval )
{
die('Could not update data: ' . mysql_error());
}
echo "Updated data successfully\n";
}
$result = mysqli_query($con,"SELECT * FROM frontpage_left_links")
or die("Error: ".mysqli_error($con));
while($row = mysqli_fetch_array($result))
{
echo '<form action="" method="post">';
echo '<div style="float:left">';
echo '<table border="1" bordercolor="#000000">';
echo '<tr>';
echo '<td>link</td>';
echo '<td><input type="text" name="linkid" value="'.$row['link'].'"></td>';
echo '</tr>';
echo '<tr>';
echo '<td>img</td>';
echo '<td><input type="text" name="imgid" value="'.$row['img'].'"></td>';
echo '</tr>';
echo '<tr>';
echo '<td>tekst</td>';
echo '<td><input type="text" name="imgid" value="'.$row['name'].'"></td>';
echo '</tr>';
echo '<tr>';
echo '<td><input type="submit" id="update" name="gem" value="Gem"</td></td>';
echo '<td><input type="hidden" name="id" value="'.$row['id'].'"></td>';
echo '</tr>';
echo '</table></div>';
echo '<div style="float:left"><center><img src="img/'.$row['img'].'"><br />'.$row['name'].'</center></div>';
echo '</form><br /><br /><br /><br /><br /><br /><br /><br />';
}
mysqli_close($con);
?>

Answer 2

try to replace :
echo '<td><input type="submit" id="update" name="gem" value="Gem"</td></td>';
with :
echo '<td><input type="submit" id="update" name="update" value="Gem"</td></td>';

Answer 3

In your form you are having update button name as gem but you are using if(isset($_POST['update'])) to run update query.
Change it to if(isset($_POST['gem']))

Answer 4

The easiest way would be to simply change the name attribute on your submit to the $_POST[] variable you used. name="update"The easiest way would be to simply change the name attribute on your submit to the $_POST[] variable you used. name="update"
Edit :: Answered already.

Answer 5

echo '<td><input type="submit" id="update" name="update" value="Gem"</td></td>';
Just delete the second td from above!!!