How can I change the default error message code

Question

I want to change the error code SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'xx@yahoo.com' for key 'email' message into something like "error email already in use"

create.php

<?php
require_once 'dbconfig.php';

if ($_POST) {

    $fname = $_POST['fname'];
    $lname = $_POST['lname'];
    $contactnum = $_POST['contactnum'];
    $email = $_POST['email'];
    $pass = $_POST['pass'];
    $lang = $_POST['lang'];

    try {

        $stmt = $db_con->prepare("INSERT INTO tbluser(fname,lname,contactnum,email,pass,lang) VALUES(:ufname,:ulname,:ucontact,:uemail,:upass,:ulang)");
        $stmt->bindParam(":ufname", $fname);
        $stmt->bindParam(":ulname", $lname);
        $stmt->bindParam(":ucontact", $contactnum);
        $stmt->bindParam(":uemail", $email);
        $stmt->bindParam(":upass", $pass);
        $stmt->bindParam(":ulang", $lang);

        if ($stmt->execute()) {
            echo "Successfully Added";
        } else {
            echo "Query Problem";
        }

    } catch(PDOException $e) {
        echo $e->getMessage();
    }
}
?>

I tried to add something like this

if (mysql_errno() == 1062) {

    echo"error email already in use!";
}

But can't make it work. Thanks for your help, I'm still new in php. Can someone advise me how to use PDO?

addform.php

<style type="text/css">
    #dis{
        display:none;
    }
</style>

<div id="dis">
    <!-- here message will be displayed -->
</div>

<form method='post' id='emp-SaveForm' action="#">

    <table class='table table-bordered'>

        <tr>
            <td>First Name</td>
            <td><input type='text' name='fname' class='form-control'  required /></td>
        </tr>

        <tr>
            <td>Last Name</td>
            <td><input type='text' name='lname' class='form-control'  required></td>
        </tr>

        <tr>
            <td>Contact Number</td>
            <td><input type='number' name='contactnum' class='form-control'  required></td>
        </tr>

         <tr>
            <td>Email</td>
            <td><input type='email' name='email' class='form-control' required /></td>
        </tr>

         <tr>
            <td>Password</td>
            <td><input type="password" name='pass' class='form-control'  required /></td>
        </tr>

         <tr>
            <td>Language</td>
            <td><input type='text' name='lang' class='form-control'  required /></td>
        </tr> 
        <tr>
            <td colspan="2">
            <button type="submit" class="btn btn-primary" name="btn-save" id="btn-save">
            <span class="glyphicon glyphicon-plus"></span> Save this User
            </button>  
            </td>
        </tr>

    </table>
</form>

Answer 1

Errors can show up in event/error logs and cause unnecessary noise if you are ever trying to find a legit error, so if you can I would avoid relying on them. Instead try:

IF (SELECT 1 = 1 FROM users WHERE email=?) THEN
BEGIN
    SELECT 0 AS Result--signals already exists to the application
END;
ELSE
BEGIN
    INSERT INTO users(columns) VALUES(values);
    SELECT LAST_INSERT_ID() AS Result;
END;
END IF;

Or something along those lines.

Answer 2

mysql_errno is part of the deprecated mysql extension - you're using PDO, so you need to check the error with it too:

if ($stmt->execute()) {
    echo "Successfully Added";
} else {
    if ($stmt->errorCode() == 1062) {
        # Here ^
        echo "error email already in use!";
    } else {
        echo "some other problem...";
    }
}