Mysql Row Deletion Fails

bits2017

Folks,

Here is a php code that lists all the rows and columns in your mysql tbl for you to select the rows (via check boxes) you want to delete and then delete them by clicking the appropriate "delete" buttons. Problem is, when I click any of the "delete" buttons, I get error flicking for a sec that there is an undefined variable $num. Not sure where to define it and how.
Confesssion :D
I actually play-paused 2 youtube videos and copy typed the code you see. That is one way I learn and gain a little work experience. Was not aware that the "each" function was deprecated until another told me.
Even though, I checked the foreach loop tutorial, here I am at a loss how to make use of it. Feeling flabbergasted in my failure!

Expand|Select|Wrap|Line Numbers

 
<?php

session_start();

require "conn.php";

require "site_details.php"; ?>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Follow Users</title>

<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">

</head>

<body>

<form name="form" action="" method="post">

<table border=1 cellpadding=1 cellspacing=1>

    <tr>

        <th>Id</th>

        <th>Username</th>

        <th>Password</th>

        <th>Email</th>

        <th>Delete</th>

    </tr>

<?php

$res=mysqli_query($conn,"SELECT * FROM users");

while($row=mysqli_fetch_array($res))

{

    echo "<tr>";

    echo "<td>"; echo $row["ids"]; ?> <input type="checkbox" name="num[]" class="other" value="<?php echo $row["ids"]; ?>" /> <?php echo "</td>";

    echo "<td>"; echo $row["usernames"]; "</td>";

    echo "<td>"; echo $row["passwords"]; "</td>";

    echo "<td>"; echo $row["emails"]; "</td>";

    echo "<td>"; echo "<input type='submit' name='submit' value='delete selected'>"; "</td>";

    echo "</tr>";

}

?>

</table>

</form>

<?php

if(isset($_POST["submit"]))

{

   $box=$_POST['num'];

   while (list ($key,$val) = @each ($box))

    {

      mysqli_query($conn,"DELETE FROM users WHERE id='$val'");

    }

?>

       <script type="text/javascript">

       window.location.href=window.location.href;

       </script>

<?php

}

?>
 
</body>

</html>

Here's another one. But, this one does not have the DELETE BUTTON. DELETE LINK instead. Same problem I'm facing on this one too. Not deleting anything.

Expand|Select|Wrap|Line Numbers

 
<?php

session_start();

require "conn.php";

require "site_details.php"; ?>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Follow Users</title>

<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">

</head>

<body>

<table border=1 cellpadding=1 cellspacing=1>

    <tr>

        <th>Id</th>

        <th>Username</th>

        <th>Password</th>

        <th>Email</th>

        <th>Delete</th>

    </tr>

<?php 

$sql = "SELECT * FROM users";

$result = mysqli_query($conn,$sql);

while($row = mysqli_fetch_array($result))

    {

        echo "<tr>";

        echo "<td>".$row['ids']."</td>";

        echo "<td>".$row['usernames']."</td>";

        echo "<td>".$row['passwords']."</td>";

        echo "<td>".$row['emails']."</td>";

        echo "<td><a href=delete2a.php?id=".$row['ids'].">Delete</a></td>";

    }
 
?>

</table>

</body>

</html>

Can some good Samaritan fix the 2 codes so we beginners can learn from your examples ? :)
I've come this far on these 2. Don't want to quit at the end.

Cheers!

Oct 16 '17 #1

Subscribe Post Reply

1915

bits2017

I corrected this:

mysqli_query($conn,"DELETE FROM users WHERE id='$val'");

to this:

mysqli_query($conn,"DELETE FROM users WHERE ids='$val'");

And this code is working:

Expand|Select|Wrap|Line Numbers

  
<?php
 
/*

ERROR HANDLING

*/

declare(strict_types=1);

ini_set('display_errors', '1');

ini_set('display_startup_errors', '1');

error_reporting(E_ALL);

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
 
include 'config.php';
 
?>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Follow Users</title>

<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">

</head>

<body>

<form name="form" action="" method="post">

<table border=1 cellpadding=1 cellspacing=1>

    <tr>

        <th>Id</th>

        <th>Username</th>

        <th>Password</th>

        <th>Email</th>

        <th>Delete</th>

    </tr>

<?php

$res=mysqli_query($conn,"SELECT ids, usernames, passwords, emails FROM users");

while($row=mysqli_fetch_array($res))

{

    echo "<tr>";

    echo "<td>"; echo $row["ids"]; ?> <input type="checkbox" name="num[]" class="other" value="<?php echo $row["ids"]; ?>" /> <?php echo "</td>";

    echo "<td>"; echo $row["usernames"]; "</td>";

    echo "<td>"; echo $row["passwords"]; "</td>";

    echo "<td>"; echo $row["emails"]; "</td>";

    echo "<td>"; echo "<input type='submit' name='submit' value='delete selected'>"; "</td>";

    echo "</tr>";

}

?>

</table>

</form>

<?php

if(isset($_POST["submit"]))

{

   $box=$_POST['num'];

   while (list ($key,$val) = @each ($box))

    {

      mysqli_query($conn,"DELETE FROM users WHERE ids='$val'");

    }

?>

       <script type="text/javascript">

       window.location.href=window.location.href;

       </script>

<?php

}

?>
 
</body>

</html>

But, how come it's working since this is deprecated:

@each

And this also working:

Expand|Select|Wrap|Line Numbers

 
<?php
 
/*

ERROR HANDLING

*/

declare(strict_types=1);

ini_set('display_errors', '1');

ini_set('display_startup_errors', '1');

error_reporting(E_ALL);

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
 
include 'config.php'; 
 
?>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<title>Follow Users</title>

<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">

</head>

<body>

<table border=1 cellpadding=1 cellspacing=1>

    <tr>

        <th>Id</th>

        <th>Username</th>

        <th>Password</th>

        <th>Email</th>

        <th>Delete</th>

    </tr>

<?php 

$sql = "SELECT ids, usernames, passwords, emails FROM users";

$result = mysqli_query($conn,$sql);

while($row = mysqli_fetch_array($result))

    {

        echo "<tr>";

        echo "<td>".$row['ids']."</td>";

        echo "<td>".$row['usernames']."</td>";

        echo "<td>".$row['passwords']."</td>";

        echo "<td>".$row['emails']."</td>";

        echo "<td><a href=delete2a.php?ids=".$row['ids'].">Delete</a></td>";

    }
 
?>

</table>

</body>

</html>

Also, why on the 1st code the concatenation is used while on the 2nd one not ?

Expand|Select|Wrap|Line Numbers

echo "<td>"; echo $row["usernames"]; "</td>";

Expand|Select|Wrap|Line Numbers

echo "<td>"; echo .$row["usernames"]; "</td>";

Do you suggest I use the concatenator or not ?

@anyone:
Any chance anyone can convert those 2 codes to use not deprecated stuffs so other beginners too can learn from your input ?

Thanks!

Oct 16 '17 #2

Similar topics

ON UPDATE CASCADE fails

by: Fraser Hanson | last post by:

Hello, I have a table which has a foreign key relationship with itself. I want and expect my updates to cascade (deletes definitely cascade as expected) but instead I just get error 1217:...

MySQL Database

remote MySQL connection fails

by: rb | last post by:

I have two XP computers, with the same version of MySQL on each. I have the same database structure and data on each. Each computer has the same user name, and each MySQL database has the same...

MySQL Database

Recovery data from Delete Query and Multi table deletion in MySQL

by: Vic | last post by:

Hi all, When I test the Delete multi table function in MySQL, DELETE table_name ...] FROM table-references I accidentally delete all data in one table. All data in that table are gone...

MySQL Database

Tracking record insertion and deletion

by: Dan Greenblatt | last post by:

I am writing some software that, among other things, needs to track the state of database tables. This includes occasionally checking the table to see what records or added, modified, or deleted....

MySQL Database

Where is Postgesql ? - MYSQL SURPRISES WITH MAXDB / MySQL appliance forLinux arrives

by: Martin_Hurst | last post by:

It would appear that MySQL is making great strides into the commercial and even the enterprise arena. I am not seeing the same news coverage being said about Postgresql. I believe Postgresql has...

PostgreSQL Database

is mysqlsb compatible with MySQL 5.0?

by: John Salerno | last post by:

My web server told me it isn't, which is why they are sticking with MySQL 4.0 for now, but I'm obsessed with using the latest versions, so I just want to be sure. According to the mysqldb download...

Python

Mysql Restore fails with strange error message

by: thomasjbs | last post by:

I'm trying to migrate a Wiki database to another server. I have zero problems backing up the database using multiple methods. But the Mysql restore fails with: ERROR 1064 at line 52: You have...

MySQL Database

MySQL insert records using MS Access

by: David | last post by:

Hi, I have a MySQL database linked to an MS Access front-end. I have an app which works fine with the local copy of the Access DB, but when run with the linked tables for MySQL, it fails. ...

MySQL Database

Vb.net 2005 database application with online mysql

by: rizwan6feb | last post by:

I have to develop a database application in vb.net 2005 with the following rules 1. The application connects with an online mysql database (i.e database resides on a remote machine) 2. The...

.NET Framework

PHP - Common Newbie Pitfalls, 2: Supplied argument is not a valid MySQL result

by: Atli | last post by:

What to discuss: What is a "MySQL resource". What causes the error. How to fix it. Common Newbie Pitfalls This article is the second installment in a series of (hopefully) many, following...

PHP

Cloud Servers without Credit Card and Email Registration: A Simpler Way to Get on the Cloud

by: CloudSolutions | last post by:

Introduction: For many beginners and individual users, requiring a credit card and email registration may pose a barrier when starting to use cloud servers. However, some cloud server providers now...

General

Easy Steps to Fix "Canon Printer Won't Connect to WiFi Network"

by: taylorcarr | last post by:

A Canon printer is a smart device known for being advanced, efficient, and reliable. It is designed for home, office, and hybrid workspace use and can also be used for a variety of purposes. However,...

General

Batch import of multiple excel files into the database

by: ryjfgjl | last post by:

If we have dozens or hundreds of excel to import into the database, if we use the excel import function provided by database editors such as navicat, it will be extremely tedious and time-consuming...

Data Management

Merging data from multiple Excel files

by: ryjfgjl | last post by:

In our work, we often receive Excel tables with data in the same format. If we want to analyze these data, it can be difficult to analyze them because the data is spread across multiple Excel files...

Data Management

Migrating Website to Cloud - Emmanuel Katto

by: emmanuelkatto | last post by:

Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud. Please let me know. Thanks! Emmanuel

General

Navigating the Data Structures and Algorithms (DSA)

by: BarryA | last post by:

What are the essential steps and strategies outlined in the Data Structures and Algorithms (DSA) roadmap for aspiring data scientists? How can individuals effectively utilize this roadmap to progress...

Algorithms / Advanced Math

Looking to do Android software development, any suggestions? Is flutter better?

by: nemocccc | last post by:

hello, everyone, I want to develop a software for my android phone for daily needs, any suggestions?

General

Is that possible of reading the .csv file in column wise and the column have different lengths ?

by: Sonnysonu | last post by:

This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...

C / C++

How to build RAID in BIOS?

by: Hystou | last post by:

There are some requirements for setting up RAID: 1. The motherboard and BIOS support RAID configuration. 2. The motherboard has 2 or more available SATA protocol SSD/HDD slots (including MSATA, M.2...

Computer Hardware