Hi people..
I got a problem which i cannot delete a a subject from my database through a page that i created.
I've made a page called edit_subject.php where there is a form which i could then delete/edit any subjects that i want.and this is the code :
<?php require_once("includes/functions.php");
?>
<?php
$connection = mysql_connect("localhost","root","mypassword");
if (!$connection) {
die ("database failed to connect " . mysql_error());
}
$db_select = mysql_select_db("newcompany");
if (!$db_select) {
die ("database failed to connect " . mysql_error());
}
?>
<?php
// naming a new function as a data query (see 'step 3' of mysql database)
/*remember that every time we wanna want to take somthg frm the database
we have to perform the steps in CRUD */
function get_subject_by_id($subject_id) {
$result_set = mysql_query("SELECT * FROM subjects WHERE id=$subject_id");
if (!$result_set) {
die("Database query failed: " . mysql_error());
}
// this is the 'use data step' (see 'step 4' of mysql database)
// this is used to echo the data (or could say 'use the data')
if ($subject = mysql_fetch_array($result_set)) {
return $subject;
}
}
?>
<?php
// naming a new function as a data query (see 'step 3' of mysql database)
/*remember that every time we wanna want to take somthg frm the database
we have to perform the steps in CRUD */
function get_page_by_id($page_id) {
$result_set = mysql_query("SELECT * FROM pages WHERE id=$page_id");
if (!$result_set) {
die("Database query failed: " . mysql_error());
}
// this is the 'use data step' (see 'step 4' of mysql database)
// this is used to echo the data (or could say 'use the data')
if ($page = mysql_fetch_array($result_set)) {
return $page;
}
}
?>
<?php
//this is to see which "subject" that being selected.Then it is pass as the argument,
//then being echo at the content area,only the menu name.
//anyway,this is the way to appear the menu name that is being selected at the navigation.
if (isset($_GET['subj'])) {
$sel_subject = get_subject_by_id($_GET['subj']);
$sel_page = NULL;
} elseif (isset($_GET['page'])) {
$sel_subject = NULL;
$sel_page = get_page_by_id($_GET['page']);
} else {
$sel_subject = NULL;
$sel_page = NULL;
}
?>
<?php
if (intval($_GET['subj']) == 0) {
redirect_to("content.php");
}
if (isset($_POST['submit'])) {
$errors = array();
// Form Validation
$required_fields = array('menu_name', 'position', 'visible');
foreach($required_fields as $fieldname) {
if (!isset($_POST[$fieldname]) || empty($_POST[$fieldname])) {
$errors[] = $fieldname;
}
}
$fields_with_lengths = array('menu_name' => 30);
foreach($fields_with_lengths as $fieldname => $maxlength ) {
if (strlen(trim(mysql_prep($_POST[$fieldname]))) > $maxlength) { $errors[] = $fieldname; }
}
if(empty($errors)) {
$id = mysql_prep($_GET['subj']);
$menu_name = mysql_prep($_POST['menu_name']);
$position = mysql_prep($_POST['position']);
$visible = mysql_prep($_POST['visible']);
$query = "UPDATE subjects SET
menu_name = '{$menu_name}',
position = {$position},
visible = {$visible}
WHERE id = {$id}";
$result = mysql_query($query,$connection);
if(mysql_affected_rows() ==1) {
// Success
$message = "The subject was succesfully updated.";
} else {
// Failed
$message = "The subject update failed.";
$message .= "<br />" . mysql_error();
}
} else {
// Errors occured
$message = "There were " . count($errors) . " errors in the form.";
}
} // end: if (isset($_POST['submit']))
?>
<head>
<meta http-equiv="Content-Language" content="en-us">
</head>
<table border="0" cellpadding="0" cellspacing="0" width="1055" height="566">
<!-- MSTableType="layout" -->
<tr>
<td valign="top" colspan="2" height="77">
<!-- MSCellType="ContentHead" -->
<p align="center"><font face="Agency FB" size="7">newcompany</font></td>
</tr>
<tr>
<td valign="top" rowspan="2" width="181">
<!-- MSCellType="NavBody" -->
<?php
// 3. Perform database query
$subject_set = mysql_query("SELECT * FROM subjects",$connection);
if (!$subject_set) {
die("Database query failed: " . mysql_error());
}
// 4. Use returned data
while ($row = mysql_fetch_array($subject_set)) {
echo "<a href='edit_subject.php?subj={$row["id"]}'>{$row['menu_name']}</a>"."<br/>";
$page_set = mysql_query("SELECT * FROM pages WHERE subject_id={$row["id"]}");
if (!$page_set) {
die ("Database query failed: " . mysql_error());
}
while ($page= mysql_fetch_array($page_set)) {
echo "<a href='content.php?page={$page["id"]}'>{$page['menu_name']}</a>"."<br/>";
}
}
?>
<a href="new_subject.php">+ Add A new Subject</a>
</td>
<td valign="top" height="52">
<!-- MSCellType="ContentHead2" -->
</td>
</tr>
<tr>
<td valign="top" height="437" width="874">
<!-- MSCellType="ContentBody" -->
<h2>Edit Subject: <?php echo $sel_subject['menu_name'];?></h2>
<?php if (!empty($message)) {
echo "$message";}
?>
<?php
// output a list of the fields that had errors
if (!empty($errors)) {
echo "Please review the following fields:<br />";
foreach($errors as $error) {
echo " - " . $error . "<br />";
}
}
?>
<form action="edit_subject.php?subj=<?php echo urlencode($sel_subject['id']); ?>" method="post">
<p>Subject name:
<input type="text" name="menu_name" value="<?php echo $sel_subject['menu_name'];?>" id="menu_name" />
</p>
<p>Position: <select name="position">
<?php
$subject_set= get_all_subjects();
$subject_count = mysql_num_rows($subject_set);
//$subject_count+1 because we are adding a subject.
for($count=1; $count <= $subject_count+1; $count++) {
echo "<option value=\"{$count}\"";
if ($sel_subject['position'] == $count) {
echo " selected";
}
echo ">{$count} </option>";
}
?>
</select>
</p>
<p>Visible:
<input type="radio" value="0" name="visible"
<?php
if ($sel_subject['visible'] == 0) {echo "checked";}
?> >No
<input type="radio" value="1" name="visible"
<?php
if ($sel_subject['visible'] == 1) {echo "checked";}
?> >Yes
</p>
<p><input type="submit" name="submit" value="Edit subject">
<a href="delete_subject.php?subj=
<?php $sel_subject['id']; ?>"
>Delete Subject</a>
</form>
<br />
<br />
<a href="content.php">Cancel</a>
<br />
</td>
</tr>
</table>
<?php
mysql_close($connection);
?>and if user need to click on delete to delete the subject which then this edit_subject.php page will make a connection to the page delete_subject.php to delete the subject.This is the code from delete_page.php :
<?php require_once("includes/functions.php");
?>
<?php
$connection = mysql_connect("localhost","root","mypassword");
if (!$connection) {
die ("database failed to connect " . mysql_error());
}
$db_select = mysql_select_db("newcompany");
if (!$db_select) {
die ("database failed to connect " . mysql_error());
}
?>
<?php
// naming a new function as a data query (see 'step 3' of mysql database)
/*remember that every time we wanna want to take somthg frm the database
we have to perform the steps in CRUD */
function get_subject_by_id($subject_id) {
$result_set = mysql_query("SELECT * FROM subjects WHERE id=$subject_id");
if (!$result_set) {
die("Database query failed: " . mysql_error());
}
// this is the 'use data step' (see 'step 4' of mysql database)
// this is used to echo the data (or could say 'use the data')
if ($subject = mysql_fetch_array($result_set)) {
return $subject;
}
}
?>
<?php
if (intval($_GET['subj']) == 0) {
header("Location: content.php");
exit;
}
$id = mysql_prep($_GET['subj']);
if ($subject = get_subject_by_id($id)) {
$query = "DELETE FROM subjects WHERE id = {$id} LIMIT 1";
$result = mysql_query($query, $connection);
if (mysql_affected_rows() == 1) {
header("Location: content.php");
exit;
} else {
// Deletion Failed
echo "<p>Subject deletion failed.</p>";
echo "<p>" . mysql_error() . "</p>";
echo "<a href=\"content.php\">Return to Main Page</a>";
}
} else {
// subject didn't exist in database
header("Location: content.php");
exit;
}
?>
<?php
mysql_close($connection);
?>but the problem is the subject is not deleted and it is only redirected me to the page of content.php which what stated in this code :
if (intval($_GET['subj']) == 0) {
header("Location: content.php");
exit;
}i think that this part of code maybe the reason of the errors because when i change the location to any other page it will redirected me to that page and doing the deletion as what i wanted..
I hope somebody could help me out..
Sory if the code is long to be gone through..
Thank You for helping :)
