与Laravel Eloquent进行多对多排序 [英] Sorting a many to many relation with Laravel Eloquent

问题描述

我有色板表，颜色表和swatch_color数据透视表.

I do have swatches table, a colors table and a swatch_color pivot table.

关系设置为:

public function colors()
{
    return $this->belongsToMany('Color');
}

public function swatches()
{
    return $this->belongsToMany('Swatch');
}

我没有问题可以检索具有颜色关系的色板

I have no problem to retrieve the swatches with the color relations

$swatches = Swatch::with('colors')->get();
return dd($swatches);

颜色始终是由5个具有hue，R，G和B属性的颜色对象组成的数组.

Colors is always an array of 5 color objects with hue, R, G, and B attributes.

现在，我想按第一种相关颜色的R值对色板进行排序.

Now I would like to sort the swatches by the R value of the first related color.

推荐答案

这是对$swatches集合进行排序所需的全部内容:

This is all you need to sort $swatches collection:

$swatches->sortBy(function ($swatch) {
  return ($color = $swatch->colors->first())
     ? $color->r
     : null;
});

另一种方法是手动joining表格.

Another way would be manual joining the tables.

您可以使用sortByDesc降序.

这篇关于与Laravel Eloquent进行多对多排序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！