Can anyone tell me why this row is being inserted twice into my database?

Question

When I click my 'Create' button I want the record to be added to my category table, however for some reason it is being added twice - even though I just click the button once. Any ideas why that may be? I can't see where else the
if (isset($_POST['create'])) { could be called from. I only have 4 pages in my whole project.

<?php require('dbConnect.php'); 

    //use the variables we created in volleyLogin.php
        session_start();
        $username = $_SESSION['username'];
        $user_id = $_SESSION['user_id'];
        echo "user name is " . $username . "<br>";
        echo "user id is " . $user_id . "<br>"; 

    if (isset($_POST['create'])) {

        $category = ($_POST['category']);
        $name = ($_POST['name']);
        $phonenumber = ($_POST['phonenumber']);
        $address = ($_POST['address']);
        $comment = ($_POST['comment']);

    //check if the category being entered is already there
        $check="SELECT COUNT(*) FROM category WHERE cat_name = '$_POST[category]'";
        $get_value = mysqli_query($con,$check);
    //check the number of values of the category being posted
        $data = mysqli_fetch_array($get_value, MYSQLI_NUM);
    //if the category name already exists in the category table
        if($data[0] >= 1) {
        echo "This Already Exists<br/>";
         }

        else if ($data[0] < 1)
        {
    //if it's not in there, then add the category in the category table.

        $sql = "INSERT INTO category VALUES(NULL, '{$category}', '$user_id')";
        $rs1=mysqli_query($con, $sql); 

        if ($con->query($sql) === TRUE) {
        echo "Yes, it's been added correctly";

        } else {
        echo "Error: " . $sql . "<br>" . $con->error;
        }

        }
    $con->close();
        }



    ?>

        <!doctype html>
        <html>
        <body>
        <h2>Create new Contact</h2>
        <form method="post" action="" name="frmAdd">
        <p><input type="text" name = "category" id = "category" placeholder = "category"></p>
        <p><input type="text" name = "name" id = "name" placeholder = "name"></p>
        <p><input type="text" name = "phonenumber" id = "phonenumber" placeholder = "phone number"></p>
        <p><input type="text" name = "address" id = "address" placeholder = "address"></p>
        <p><input type="text" name = "comment" id = "comment" placeholder = "comment"></p>

        <p><input type="submit" name = "create" id = "create" value = "Create new Contact"></p>
        <a href="exit.php">Exit</a>

        </form>

        </body>
        </html>

score 4 · Accepted Answer · answered Nov 16 '16 at 23:11

4

You're running the $sql query twice, with two different methods:

$rs1=mysqli_query($con, $sql); 

        if ($con->query($sql) === TRUE) {

That's why you're getting duplicate entries.

You should either remove $rs1 as it's not being used, or verify it's value on the conditional instead of running the function again.

answered Nov 16 '16 at 23:11

Phiter

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Thanks. I don't understand why it works but it does. I'll read up on those sections now in a new book I got, PHP for the Web. I'll accept your answer in 9 minutes, apparently. – CHarris Nov 16 '16 at 23:17
2

It's ok. You probably just mixed up two different things. While you're at it, check this out: [How can I prevent SQL Injection in PHP](http://stackoverflow.com/questions/60174/how-can-i-prevent-sql-injection-in-php). Your code is very vulnerable. Never put input data into the query directly. Never trust them, they can go all hacky hacky. Use `mysqli_real_escape_string` or use prepared statements. – Phiter Nov 16 '16 at 23:19

Can anyone tell me why this row is being inserted twice into my database?

1 Answers1