PHP while while顯示類別，然後它下面的產品

Question

我試圖顯示產品的列表取決於他們在我的程序中的類別。到目前爲止，這是我的代碼看起來像：

$query = "SELECT products_name, categories_desc, id, price 
     FROM products, categories 
     WHERE products.categories_id = categories.categories_id"; 

$result = mysql_query($query); 

while($row=mysql_fetch_array($result)){ 
    echo "<b>" . $row['categories_desc'] . "</b><br>"; 

    while($row=mysql_fetch_array($result)){ 
     echo "<input type='checkbox' name='" . $row['products_name'] . "' value='" . $row['price'] . "'>" . $row["products_name"] . "</br>"; 
    } 
} 

但很明顯，我做錯了什麼。它只顯示第一類，然後顯示所有產品。幫助，任何人？提前致謝！

Answer 1

你不需要第二個循環。這是你程序中的錯誤。

它應該是這樣的：

$query = "SELECT products_name, categories_desc, id, price 
     FROM products, categories 
     WHERE products.categories_id = categories.categories_id"; 

$result = mysql_query($query); 
$last_category=''; 
while($row=mysql_fetch_array($result)){ 
    if ($last_category!=$row['categories_desc']){ 
     echo "<b>" . $row['categories_desc'] . "</b><br>"; 
     $last_category=$row['categories_desc']; 
    } 

    echo "<input type='checkbox' name='" . $row['products_name'] . "' value='" . $row['price'] . "'>" . $row["products_name"] . "</br>"; 
}