while循环和数组问题

Question

$result=array();
$table_first = 'recipe';
$query = "SELECT * FROM $table_first";
$resouter = mysql_query($query, $conn);



while ($recipe = mysql_fetch_assoc($resouter, MYSQL_ASSOC)){
   $result['recipe']=$recipe;

$query2="SELECT ingredients.ingredient_id,ingredients.ingredient_name,ingredients.ammount FROM ingredients where rec_id = ".$recipe['rec_id'];
$result2 = mysql_query($query2, $conn);

 while($ingredient = mysql_fetch_assoc($result2)){


        $result['ingredient'] = $ingredient;

 }

 echo json_encode($result);
}

这段代码显示了所有食谱，但只显示了最后的配料，即

{"recipe":{"rec_id":"14","name":"Spaghetti with Crab and Arugula","overview":"http:\/\/www","category":"","time":"2010-11-11 14:35:11","image":"localhost\/pics\/SpaghettiWithCrabAndArugula.jpg"},
"ingredient":{"ingredient_id":"55","ingredient_name":"test","ammount":"2 kg"}}{"recipe":{"rec_id":"15","name":"stew recipe ","overview":"http:\/\/www","category":"","time":"2010-11-11 14:42:09","image":"localhost\/pics\/stew2.jpg"},
"ingredient":{"ingredient_id":"25","ingredient_name":"3 parsnips cut into cubes","ammount":"11"}}

我想输出与配方id 14相关的所有配料记录，这只是打印最后一种配料。

Answer 1

$result['ingredient'] = $ingredient;

每次将变量$result['ingredient']替换为最新的$ingredient值，并以最后返回的值结束，则应使用：

$result['ingredient'][] = $ingredient;

为每个$ingredient在$result['ingredient']数组中增加一个/创建一个新值。然后，您可以根据需要输出此数组。使用print_r($result['ingredient'])将向您显示其content...to，请自己查看尝试：

while($ingredient = mysql_fetch_assoc($result2)){
        $result['ingredient'][] = $ingredient;


}

print_r($result['ingredient']);

Answer 2

如果我正确理解了您想要做的事情，那么有一种方法可以对代码进行大量优化，方法是使用连接在单个查询中获取食谱和配料：

$recipes = array();
$recipe_ingredients = array();

$query = "SELECT * FROM recipe LEFT JOIN ingredients ON ingredients.rec_id=recipe.rec_id ORDER BY recipe.rec_id DESC";

$resouter = mysql_query($query, $conn);

$buffer_rec_id = 0;
$buffer_rec_name = "";
$buffer_rec_cat = "";

while( $recipe = mysql_fetch_array($resouter) )
{

  if( $buffer_rec_id != $result['recipe.rec_id'] )
  {
      $recipes[] = array( $buffer_rec_id, $buffer_rec_name, $buffer_rec_cat, $recipe_ingredients);

      $recipe_ingredients = array(  );

      $buffer_rec_id = $result['recipe.rec_id'];
      $buffer_rec_name = $result['recipe.rec_name'];
      $buffer_rec_cat = $result['recipe.rec_category'];
  }
  else
  {
      $recipe_ingredients[] = array( $result['ingredient_id'], $result['ingredient_name'], $result['ammount'] );

  }

}

$print_r($recipes);

这段代码应该为您提供一个多维数组，您可以在以后使用它来获取所需的数据。

我让您修改代码以获得所需的信息。