community-service/app/Repositories/CategoryRepository.php

<?php
/**
 * Created by PhpStorm.
 * User: Administrator
 * Date: 2019-06-15
 * Time: 11:16
 */

namespace App\Repositories;

use App\Models\Category;
use App\Models\CategoryTopic;

class CategoryRepository {

    public function __construct(Category $category,CategoryTopic $categoryTopic) {
        $this->category = $category;
        $this->categoryTopic = $categoryTopic;
    }
    //列表
    public function lists($request)
    {
        $where = [];
        if(isset($request['is_suggest']) && $request['is_suggest'] == 1){
            $where [] = ['is_suggest', 1];
            $data = [];
        }else{
            $data = [
                [
                    'id' => -2,
                    'name' => '热门',
                    'img' => config('customer.category_hot_img')
                ],
                [
                    'id' => -1,
                    'name' => '我的话题',
                    'img' => config('customer.category_my_img')
                ]
            ];
        }
        $categories =  $this->category->select('id', 'name', 'img')->where($where)->limit(50)->get()->toArray();
        return array_merge($data, $categories);
    }
    //获取多个话题
    public function getTopics($ids){
        $ids = explode(',',$ids);
        return $this->categoryTopic
            ->leftJoin('topic', 'category_topic.topic_id', '=', 'topic.id')
            ->where('topic.is_suggest',1)
            ->whereIn('category_topic.category_id',$ids)
            ->select('topic.id','topic.name','topic.is_suggest')
            ->groupBy('topic.id')
            ->get();
    }
}