Question

I got help for a previous problem/question, and just realized that the script I was given returns the “wrong” number/value (yet does not trigger php/mysql errors). Here’s the values:

ingredient #1: 20.216 calories

ingredient #2: 134.4564 calories

The script should return: 154.67 but instead returns: 91.35

The code:

<?php
//The Recipe selected
$recipe_id = $_POST['recipe_id'];

/*****************************************
 * Total CALORIES in this recipe
 *****************************************/

echo '<h4>Total calories in this recipe:</h4>';

$result = mysql_query(
  "SELECT SUM(ingredient_calories), ingredient_amount
  FROM recipe_ingredients
  INNER JOIN ingredients USING (ingredient_id)
  WHERE recipe_id = $recipe_id");

while ($row = mysql_fetch_array($result)) {
  $recipe_calories = (
    $row['SUM(ingredient_calories)']
    * $row['ingredient_amount']);
}
echo number_format($recipe_calories, 2);

mysql_free_result($result);
?>

The ingredients table, stores the default values and serving size for each ingredient.

The recipes table, stores/sets the recipe_id, and other data unrelated to the query)

The recipe_ingredients table, maps the ingredient(s) within a recipe and stores the amount(s) used in the recipe.

I’m sure it’s a problem with the query, but I too wet behind the ears to determine the problem. Any help is greatly appreciated 🙂

UPDATE: Here’s the table data, as requested

ingredients
-----------
ingredient_id
ingredient_name
ingredient_calories

recipes
-------
recipe_id
recipe_name

recipe_ingredients
------------------
recipe_id (fk)
ingredient_id (fk)
ingredient_amount

Answer 1

FIGURED IT OUT!

Made the following adjustments:

$result = mysql_query(
  "SELECT ingredient_calories, ingredient_amount
  FROM recipe_ingredients
  INNER JOIN ingredients USING (ingredient_id)
  WHERE recipe_id = $recipe_id");

while ($row = mysql_fetch_array($result)) {
  $recipe_calories += (
    $row['ingredient_calories']
    * $row['ingredient_amount']);
}
echo number_format($recipe_calories, 2);

Problem solved 🙂