Query was Empty error in php using PDO [duplicate] - php

Question

I am trying to build a cart using MySQL. I keep getting this error 'Query was empty' when I run this code. Please help I've tried several things such as putting the variables inside the string instead of concatenating it.
<?php ob_start(); ?><?php require_once("../include/membersite_config.php"); ?>
<?php
require('../products_reloaded/config.php');
session_start();
$user = $_REQUEST['user'];
$user = mysql_real_escape_string($user);
$itemNum = $_REQUEST['itemNum'];
$itemNum = mysql_real_escape_string($itemNum);
$quantity = $_POST['quantity'];
$quantity = intval($quantity);
$CheckForExistence = mysql_query("select * from cart where user = '$user' and p_number = '$itemNum'" );
$alreadyExistsChecker = mysql_num_rows($CheckForExistence);
if($alreadyExistsChecker >= 1)
{
$quantity +=1;
echo "this is equal to $alreadyExistsChecker";
}
if($alreadyExistsChecker == 0)
{
$getQuery = mysql_query("select * from product where p_number = '$itemNum'");
while($row = mysql_fetch_array($getQuery))
{
$name = $row['p_name'];
$image = $row['p_url'];
$price = $row['p_price'];
}
$name = mysql_real_escape_string($name);
$image = mysql_real_escape_string($image);
$price = intval($price);
$query = mysql_query('insert into cart values('.$user.','.$itemNum.','.$name.', '.$image.','.$quantity.', '.$price.')');
$result = mysql_query($query);
if (!$result) {
print "An error occured: " . mysql_error() . "\n";
}
}
header('http://www.definitionxjm.com/shopping/viewCart.php');
?>

Answer 1

What do you try to achieve with this line?
$result = mysql_query($query);
Just delete it and change the line above to
$result = mysql_query('insert into cart values('.$user.','.$itemNum.','.$name.', '.$image.','.$quantity.', '.$price.')');
[Edit]
Btw. you are forgetting the " (quotes) inside the query which causes an sql error to occur, leading to $query = false (see manual). $query (false) then gets converted to string, resulting in '' (an empty string) which you pass to mysql_query and that generates an "Query was empty"-Message, as it should because you tried to send an empty query.

Answer 2

It can also mean the table which is in consideration is empty.This condition arises when the "DELETE FROM table_name where ;" is used. Here if the table "table_name" has no data, it cannot delete anything and hence it shows an error stating that the query is empty.