Question

我有两张桌子：“汽车”和“经销商”：

汽车表

id_car | name_car     | etc. 
----------------------------    
  1    | A3 Sportback | etc.
  2    | Ranger       | etc.
  3    | Transit Van  |etc.
  4    | Cayman       | etc.
 etc.  | etc.         | etc.

经销商表

在deal_cars列中，我将对应汽车的ID作为数组插入。

deal_id | deal_name | deal_cars | etc.
--------------------------------------
  1     | Ford      | 2,3       | etc.
  2     | Audi      | 1         | etc.
  3     | Porsche   |  4        | etc.
 etc.   | etc.      | etc.      |

我会看到一个显示以下信息的页面：

经销商名称 - 汽车

福特 - Ranger，Transit Van
奥迪 - A3 Sportback
Cayman - Porsche

提取经销商名称没问题，但我不知道如何从ID中提取汽车名称。

我试过了：

$dealerships_sql = $data->query("SELECT * FROM dealerships ORDER BY deal_name ASC"); 
while($dealerships_obj = $data->extract($dealerships_sql)){ 
  //Dealerships data 
    $deal_id[] = $dealerships_obj->deal_id; 
    $deal_name[] = $dealerships_obj->deal_name; 
    etc etc      

  //Try to get cars ids and turn them in cars names.
       $deal_cars[] = $dealerships_obj->deal_cars; 
       $deal_cars[] = explode(',',$deal_cars);    
       $cars = array();  
         foreach ($deal_cars AS $deal_car) { 
            $cars_sql = $data->query("SELECT name_car FROM cars WHERE id_car = '$deal_car'"); 
              while($cars_obj = $data->extract($cars_sql)){ 
                 $cars[] = stripslashes($cars_obj->name_car)." ";    
               } 
         }  
}

我使用smarty作为模板引擎，因此我指定了一些变量：

$smarty->assign ("deal_id", $deal_id);
$smarty->assign ("deal_name", $deal_name);
etc etc.

$smarty->assign ("cars", $cars);

我的模板是：

<table border="1">
<tr> 
<td>Dealership</td>
<td>Cars</td>
</tr>
{section name="foo" loop=$deal_name}
<tr> 
<td>{$deal_name[foo]}</td>
<td>{$cars[foo]}</td>  
</tr>
{/section}
</table>

但代码返回：

福特 - 游侠
奥迪 - A3 Sportback
Cayman - Porsche

它仅显示每个经销商的第一辆汽车（阵列中的第一个元素）。我该如何解决这个问题？

Answer 1

我认为您的数据库设计不适合这里。

汽车表

id_car | name_car     | etc. 
----------------------------    
  1    | A3 Sportback | etc.
  2    | Ranger       | etc.
  3    | Transit Van  | etc.
  4    | Cayman       | etc.
 etc.  | etc.         | etc.

经销商表

deal_id | deal_name | etc.
---------------------------
  1     | Ford      | etc.
  2     | Audi      | etc.
  3     | Porsche   | etc.
 etc.   | etc.      |

经销商到汽车表

dealerid | carid 
    1    |   2
    1    |   3
    2    |   1
   etc.  |  etc.

如您所见，我为另外两张桌子之间的关系做了另一张表。

$dealerships_sql = $data->query("SELECT * FROM dealerships ORDER BY deal_name ASC"); 
$dealers = array();
while($dealerships_obj = $data->extract($dealerships_sql)){ 
  //Dealerships data, use object
    $dealerid = $dealerships_obj->deal_id;
    $dealers[$dealerid]['dealer'] = $dealerships_obj;     

  // Cars
    $cars = array();
    $car_sql = $data->query("SELECT name_car FROM cars JOIN dealerToCars ON carid = id_car JOIN dealer ON deal_id = dealerid WHERE deal_id = " . $dealerid);
  // now you have all cars from the selected dealer
    while ($cars_obj = $data->extract($car_sql))
    {
           $cars[] = stripslashes($cars_obj->name_car);
    }

  // Assign Cars to dealer
    $dealers[$dealerid]['cars'] = $cars;
}

现在，所有经销商都在经销商处购买汽车。

由于你使用的是smarty，只需将整个数组传递给smarty，让其余的数组在它的模板中做得很聪明。 Smarty能够使用数组和对象，因此您无需将其拆分为多个数组：

$smarty->assign ("dealers", $dealer);

因为我不知道你的课程，你可能需要添加一些getter或setter，或者只是公开属性，所以smarty可以访问它们：

<table border="1">
<tr> 
<td>Dealership</td>
<td>Cars</td>
</tr>
{foreach $dealers as $dealer}
<tr> 
<td>{$dealer['dealer']->deal_name}</td>
<td>{foreach $dealer['cars'] as $car}{$car}, {/foreach}</td>  
</tr>
{/foreach}
</table>

也许您需要查看模板中的标识符。

（我正在使用smarty 3）

Answer 2

我认为你应该拥有每辆车的经销商行（这样你就可以通过JOIN获得所有信息并轻松解析）。

Answer 3

最好的方法是一次性完成所有事情，你可以这样做：

select 
    d.deal_name, 
    group_concat(c.name_car order by c.name_car separator ', ')
from dealerships d
join cars c on find_in_set(c.id_car, d.deal_cars) > 0
group by d.deal_name;

或（作为单独的字段）：

select d.deal_id, d.deal_name, c.id_car, c.name_car
from dealerships d
join cars c on find_in_set(c.id_car, d.deal_cars) > 0;

Foreach在一个循环中

3 个答案: