Question

我有以下关系：

Tool:
-----
id
name
description


Competency:
-----------
id
name
description
tool_id


Indicator:
----------
id
name
description
competency_id

我正在尝试获取直接属于指定工具的所有指标（即孙子）。关系是工具具有很多能力，而能力有很多指标。

到目前为止我的（伪）代码是：

hasManyThrough('Indicator', 'Competency', 'tool_id', 'competency_id')->where('tool_id', '=', 1)->get();

我认为我走的是正确的路线，但无法正确使用代码。

Answer 1

获取指定能力的指标。

$indicatorsOfCompetency = Indicator::where("competendy_id", $yourCompetencyID)->get();

或者，取决于您的 laravel关系名称：

$competency = Competency::find($yourCompetencyID);

$indicatorsOfCompetency = $competency->indicators()->select(["id","field1","field2"]);

获取指标时，他的能力与指定的工具相关。

// Note: Depending of your Laravel version, could be "lists" or "pluck" function.
$competencyIDS = Competency::where("tool_id", $yourToolID)->lists("id");

$indicators = Indicator::whereIn("competency_id", $competencyIDS);

或更多雄辩，使用whereHas()：

$indicators = Indicator::whereHas("competency", function($qCompetency) use ($yourToolID){
    $qCompetency->whereHas("tools", function($qTool) use($yourToolID){
        $qTool->where("id", $yourToolID);
    });
});

Laravel Eloquent - 获得grandparent_id匹配的'孙子'的方法

1 个答案: