嵌套的mysql while循环不返回预期的结果

Question

我有2个表，我试图使用嵌套的while循环列出所有可能性。不幸的是，我只获得了一小部分结果。任何帮助深表感谢。

产品表

Product_ID | Product_Name | Product_Desc
0          | Box          | Big Box     
1          | Toy          | Nice Toy  

城市表

City_ID    | City_Name 
0          | Cincinnati    
1          | Detroit
2          | San Francisco
3          | San Diego
4          | New York

预期的预期结果：

0 Box Big Box 0 Cincinnati
0 Box Big Box 1 Detroit
0 Box Big Box 2 San Francisco
0 Box Big Box 3 San Deigo
0 Box Big Box 4 New York
1 Toy Nice Toy 0 Cincinnati
1 Toy Nice Toy 1 Detroit
1 Toy Nice Toy 2 San Francisco
1 Toy Nice Toy 3 San Diego
1 Toy Nice Toy 4 New York

我的错误结果：

0 Box Big Box 0 Cincinnati
1 Toy Nice Toy 0 Cincinnati

这是我的代码：

query = "SELECT * FROM Products";
$result = mysqli_query($con, $query);

$query2 = "SELECT * FROM Cities";
$result2 = mysqli_query($con, $query2);


while($row = mysqli_fetch_assoc($result))
    {
         $product_id = $row['Product_ID'];
         $product_name = $row['Product_Name'];
         $product_desc = $row['Product_Desc'];

        while($row = mysqli_fetch_assoc($result2))
        {
        $city_id = $row['City_ID'];
        $city_name = $row['City_Name'];
        }

    echo "$product_id $product_name $product_desc $city_id $city_name\n";

}

不幸的是，上述情况不起作用，我只是得到了这个结果。我应该使用foreach产品吗？

Answer 1

实际上，您可以使用单个查询获得相同的结果，而无需使用嵌套循环

$query = "SELECT p.*,c.* FROM Products p,City c";