在 Kohana 中列出类别和产品时分离 SQL、PHP 和视图
-
19-09-2019 - |
题
我想将我的小型网站迁移到 Kohana,并且尝试将 SQL、PHP 和视图分开,但我在这方面遇到了一些问题。
我必须要桌子。每个类别可以有多个产品。
类别表
- ID
- 类别
产品表
- ID
- 类别_id
- 产品
这是我之前的代码(转换为 Kohana 的查询生成器):
$categories = DB::select('id', 'category')
->from('categories')
->as_object()
->execute();
foreach ($categories as $category)
{
echo '<b>'.$category->category.'</b><br />';
$products = DB::select('product')
->from('products')
->where('category_id', '=', $category->id)
->as_object()
->execute();
foreach($products as $product)
{
echo $product->product.'<br />';
}
echo '<hr />';
}
我想做同样的事情,只是在视图文件中除了回显变量之外我不想使用它。
更新:我更喜欢不使用 Kohana 的 ORM 模块的解决方案。顺便说一句,我正在使用 Kohana 3.0
更新2:
我已经接受了 Lukasz 的最后一个解决方案,但需要进行一些修改才能完全实现我想要的效果(请注意,这是针对 Kohana 3.0 的,而 Lukasz 使用的是旧版本):
SQL代码:
$products = DB::select(array('categories.category', 'cat'), array('products.product', 'prod'))
->from('categories')
->join('products','RIGHT')
->on('products.category_id','category.id')
->as_object()
->execute();
视图文件中的代码(解释见注释):
// Let's define a new variable which will hold the current category in the foreach loop
$current_cat = '';
//We loop through the SQL results
foreach ($products as $product)
{
// We're displaying the category names only if the $current_cat differs from the category that is currently retrieved from the SQL results - this is needed for avoiding the category to be displayed multiple times
// At the begining of the loop the $current_cat is empty, so it will display the first category name
if($curren_cat !== $product->cat)
{
// We are displaying a separator between the categories and we need to do it here, because if we display it at the end of the loop it will separate multiple products in a category
// We avoid displaying the separator at the top of the first category by an if statement
if($current_cat !== '')
{
//Separator
echo '<hr />';
}
// We echo out the category
echo '<b>'.$product->cat.'</b><br />';
// This is the point where set the $current_cat variable to the category that is currently being displayed, so if there's more than 1 product in the category the category name won't be displayed again
$current_cat = $product->cat;
}
// We echo out the products
echo $product->prod.'<br />';
}
我希望这对其他人也有帮助,如果有人有更好的解决方案,请分享!
解决方案
这应该有效:
$categories = ORM::factory('category')->find_all();
foreach ($categories as $category)
{
echo '<b>'.$category->category.'</b><br />';
$products = ORM::factory('product')->where('category_id',$category->id)->find();
foreach($products as $product)
{
echo $product->product.'<br />';
}
echo '<hr />';
}
我假设您为每个表创建了模型?如果没有,请阅读 这里.
更好的 如果将数据层和视图层分开。并在模型文件中创建类别和产品之间的关系。然后在控制器中你应该只调用这个:
$categories = ORM::factory('category')->find_all();
$view = new View('yourView');
$viem->categories = $categories;
并在视图文件中:
foreach ($categories as $category)
{
echo '<b>'.$category->category.'</b><br />';
foreach($category->products as $product)
{
echo $product->product.'<br />';
}
echo '<hr />';
}
您不必为每一行调用第二个查询。Kohana ORM 将为您做到这一点。您所要做的就是创建适当的模型:
class Category_Model extends ORM {
protected $has_many = array('products');
}
class Product_Model extends ORM {
protected $belongs_to = array('category');
}
另一种方法: 您可以加入表格类别和产品
$products = DB::select('categories.category AS cat','products.product AS prod')
->from('categories')
->join('products','products.category_id','category.id')
->as_object()
->execute();
进而:
$current_cat = '';
foreach($products as $product)
{
if($current_cat != $products->cat)
{
echo '<b>'.$products->cat.'</b><br />';
$current_cat = $products->cat;
}
echo $product->prod.'<br />';
}
其他提示
只是一个快速的想法:
当使用 ORM 方法时,我认为您可以使用 with() 方法实现与连接查询相同的效果:
$products = ORM::factory('product')
->with('category')
->find_all();
$view = new View('yourView');
$viem->products = $products;
我没有足够的时间去搞乱它,但这就是我会尝试的。
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