I want to show an error if duplicates are there in database using php and mysql

Question

I'm trying to show an error while entering duplicates using php and mysql, but i'm not getting how to complete, please give an solution........

this is my code:

mysql_query(
"INSERT INTO productcost (product, productCategory, model, purchasePrice, mrp, customerPrice, marginCustomer, dealerPrice, marginDealer) 
VALUES ('" . $_POST["product"] . "','" . $_POST["productCategory"] . "','" . $_POST["model"] . "','" . $_POST["purchasePrice"] . "','" . $_POST["mrp"] . "','" . $_POST["customerPrice"] . "','" . $_POST["marginCustomer"] . "','" . $_POST["dealerPrice"] . "', '" . $_POST["marginDealer"] . "')");

$current_id = mysql_insert_id();

if(!empty($current_id)) {
$message = "New Product Added Successfully";
}

}

Answer 1

You have to create unique key in productcost table , using unique fields like (product, productCategory, model). Now execute insert query, if there is a recode in the table return error . now you can handle error and give message.

    try{ 
    mysql_query("INSERT INTO productcost (product_key_id,product, productCategory,model,purchasePrice, mrp, customerPrice, marginCustomer, dealerPrice, marginDealer) 
VALUES 
('" . $_POST["created_product_id"] . "','" . $_POST["product"] . "','".$_POST["productCategory"] . "','" . $_POST["model"] . "','".$_POST["purchasePrice"] . "','" . $_POST["mrp"] . "','".$_POST["customerPrice"] . "','" . $_POST["marginCustomer"] . "','".$_POST["dealerPrice"] . "', '" . $_POST["marginDealer"] . "')");

    return TRUE;
    }
    catch(Exception $e){
      return FALSE;
    }

or you can check is there a recode in table before insert

select count(*) as cc from doc_upload where product_key_id = $_POST["created_product_id"];

Answer 2

To show an error message while entering duplicates:

// First check there are same data available or not using a query by counting the row
$sqlCheck = "SELECT COUNT(`id`) WHERE product = '" . $_POST["product"] . "' AND productCategory = '" . $_POST["productCategory"] . "' AND model = '" . $_POST["model"] . "'"; // You have to add mroe thing in where clause
$CheckQuery = mysql_query($sqlCheck);

// if there is no duplicate data
// 
if ($CheckQuery > 0) {
    # code...

mysql_query(
"INSERT INTO productcost (product, productCategory, model, purchasePrice, mrp, customerPrice, marginCustomer, dealerPrice, marginDealer) 
VALUES ('" . $_POST["product"] . "','" . $_POST["productCategory"] . "','" . $_POST["model"] . "','" . $_POST["purchasePrice"] . "','" . $_POST["mrp"] . "','" . $_POST["customerPrice"] . "','" . $_POST["marginCustomer"] . "','" . $_POST["dealerPrice"] . "', '" . $_POST["marginDealer"] . "')");

$current_id = mysql_insert_id();

if(!empty($current_id)) {

    $message = "New Product Added Successfully";

}

} else {

        $message = "Data is Duplicated";
}

Note : I'm Giving you an Example . this is how you have to check duplicate data