在 Silverstripe 模型中查询远程表

发布于 2024-12-07 11:59:34 字数 548 浏览 0 评论 0原文

我试图从另一种页面类型的页面类型中获取字段“成本”的总和。 (ProjectCategory)，就像这样：

class ProjectCategory  extends Page {
 static $belongs_many_many = array( 
  'RelateToProject' => 'Project' 
); 

function totalCost(){
    $sqlQuery = new SQLQuery( 
     "SUM(Project.cost)", // Select 
     "Project", // From 
    "what to do here?" // Where (optional) 
    ); 
    $totalVisits = $sqlQuery->execute()->value();

    return $totalVisits;
}

我该为 where 位做什么？我怎样才能获得该类别的总成本？（如果我将 where 留空，它将返回每个类别的所有项目成本的总和 - 这不好）。

原文

I'm trying to get a sum of a field "cost" from a page type from another page type. (ProjectCategory), like this:

class ProjectCategory  extends Page {
 static $belongs_many_many = array( 
  'RelateToProject' => 'Project' 
); 

function totalCost(){
    $sqlQuery = new SQLQuery( 
     "SUM(Project.cost)", // Select 
     "Project", // From 
    "what to do here?" // Where (optional) 
    ); 
    $totalVisits = $sqlQuery->execute()->value();

    return $totalVisits;
}

What do I do for the where bit? How can I get the sum of cost for just this Category? (If I leave the where blank it returns the sum of all project costs for every category - which is no good).

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吃→可爱长大的 2024-12-14 11:59:34

“where”部分应该是：

"ID = " . $this->RelateToProjectID

哦，等等，上面的内容仅适用于 $has_one，但您使用的是 Many_many 关系。

以下应该可以解决您的 Many_many 关系：

构建相关项目的 ID 数组：

$projects = $this->RelateToProject();
$projectIDs = array();
if($projects) {
  foreach($projects as $project) {
    $projectIDs[] = $project->ID;
  }
}

然后在“where”语句中使用它们，如下所示：

"ID IN (" . join(',',$projectIDs) . ")"

the "where" part should be:

"ID = " . $this->RelateToProjectID

oh, wait, the above will only work für $has_one, but you're using a many_many relationship.

the following should do the trick for your many_many relationship:

build an array of IDs of related projects:

$projects = $this->RelateToProject();
$projectIDs = array();
if($projects) {
  foreach($projects as $project) {
    $projectIDs[] = $project->ID;
  }
}

then use them in your 'where' statement like so: