Sql error when updating record

Question

1.00/5 (1 vote)

See more:

I get this error "Erorr while updating record : You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near line 1" when i try to update the sql databse
I cant see anything wrong with the sql syntax

<?php 
 
require_once 'db_connect.php';
 
if($_POST) {
    $fname = $_POST['fname'];
    $lname = $_POST['lname'];
    $age = $_POST['age'];
    $contact = $_POST['contact'];
 
   
    $id = ''; 
if( isset( $_GET['id'])) {
    $id = $_GET['id']; 
} 
 
    $sql = "UPDATE members SET fname = '$fname', lname = '$lname', age = '$age', contact = '$contact' WHERE id = {$id}";
    if($connect->query($sql) === TRUE) {
        echo "<p>Succcessfully Updated</p>";
        echo "<a href='../edit.php?id=".$id."'><button type='button'>Back</button></a>";
        echo "<a href='../index.php'><button type='button'>Home</button></a>";
    } else {
        echo "Erorr while updating record : ". $connect->error;
    }
 
    $connect->close();
 
}
 
?>

<!DOCTYPE html>
<html>
<head>
    <title>Add Member</title>
 
    <style type="text/css">
        fieldset {
            margin: auto;
            margin-top: 100px;
            width: 50%;
        }
 
        table tr th {
            padding-top: 20px;
        }
    </style>
 
</head>
<body>
 
<fieldset>
    <legend>Add Member</legend>
 
    <form action="create.php" method="post">
        <table cellspacing="0" cellpadding="0">
            <tr>
                <th>First Name</th>
                <td><input type="text" name="fname" placeholder="First Name" /></td>
            </tr>     
            <tr>
                <th>Last Name</th>
                <td><input type="text" name="lname" placeholder="Last Name" /></td>
            </tr>
            <tr>
                <th>Age</th>
                <td><input type="text" name="age" placeholder="Age" /></td>
            </tr>
            <tr>
                <th>Contact</th>
                <td><input type="text" name="contact" placeholder="Contact" /></td>
            </tr>
            <tr>
                <td><button type="submit">Save Changes</button></td>
                <td><a href="index.php"><button type="button">Back</button></a></td>
            </tr>
        </table>
    </form>
 
</fieldset>
 
</body></html>

What I have tried:

cant find a viable solution to this issue

Posted 24-Oct-21 6:18am

Member 15405725

Updated 24-Oct-21 7:57am

Add a Solution

2 solutions

Add a Solution

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Wendelius · Answer 1 · 2021-10-24T07:23:00

Solution 1

One reason why the statement can fail is because you don't use parameters. This leaves you vulnerable to SQL injection, conversion problems, etc.

For an example how to use parameters from PHP, have a look at PHP: Prepared Statements - Manual[^]

Posted 24-Oct-21 7:23am

Wendelius

OriginalGriff · Answer 2 · 2021-10-24T07:57:00

To add to what Wendelius has said, never concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Always use Parameterized queries instead.

When you concatenate strings, you cause problems because SQL receives commands like:

SQL

SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'

The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:

SQL

SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'

Which SQL sees as three separate commands:

SQL

SELECT * FROM MyTable WHERE StreetAddress = 'x';

A perfectly valid SELECT

SQL

DROP TABLE MyTable;

A perfectly valid "delete the table" command

SQL

--'

And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.

So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?

Fix that throughout your app, and the problem you have noticed will probably disappear at the same time ...

Sql error when updating record

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0

Sql error when updating record

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0

Existing Members

...or Join us