Question

我正在尝试在聚合中进行查找，但是在尝试获取与数组中的元素匹配的所有文档时遇到了问题。目标是获得“ $ services”和“ $$ services”之间交点的所有雇员。这两个是ObjectID的数组。查找将在员工集合中进行。这是我尝试过的方法，但之后不知道如何匹配：

{
            $lookup: {
                from: collection_names.EMPLOYEE,
                let: { services: "$services._id" },
                pipeline: [  
                    {
                        $project: {
                            _id: 0, 
                            intersection: {  $setIntersection: ["$services", "$$services"] },
                        }
                    },
                    // {
                    //     $match: { }
                    // }
                ],
                as: "employees"
            }
        },

这是完整的汇总：

collection.aggregate([
        {
            $geoNear: {
                near: { type: "Point", coordinates: correct_format_loc, },
                key: 'location',
                distanceField: 'location.dist',
                maxDistance: range * 1000,  // 1000 meters
                query: { name: re },
                spherical: true,
            }
        },
        {
            $lookup: {
                from: collection_names.SERVICE,
                let: { business: "$_id" },
                pipeline: [
                    { $match: { $expr: { $eq: ["$business", "$$business"] } } },
                    {
                        $project: {
                            _id: 1,
                            name: 1,
                            price: 1,
                            category: 1,
                            duration: 1,
                        }
                    } 
                ],
                as: "services"
            }
        },
        {
            $lookup: {
                from: collection_names.EMPLOYEE,
                let: { services: "$services._id" },
                pipeline: [  
                    {
                        $project: {
                            _id: 0, 
                            intersection: {  $setIntersection: ["$services", "$$services"] },
                        }
                    },
                    // {
                    //     $match: { }
                    // }
                ],
                as: "employees"
            }
        },
        { 
            $project: {
                 name: "$name",
                 address: "$address",
                 location: "$location",
                 contact: "$contact",
                 description: "$description",
                 image_paths: "$image_paths",
                 services: '$services',
                 employees: '$employees',
                 rating_avg: {
                     $avg: "$services.rating"
                 }
            }
         },
    ]).toArray()

Answer 1

我发现解决方案在两个投影之间有一个匹配项。这些更改是在我写的问题的最后一个$lookup中完成的。

我所做的是获取相交并将其投影为新属性，然后与表达式匹配，然后删除不需要的不必要属性。更改后的外观如下：

{
            $lookup: {
                from: collection_names.EMPLOYEE,
                let: { services: '$services._id' },
                pipeline: [
                    {
                        $project: {
                            name: 1,
                            description: 1,
                            rating: 1,
                            image_path: 1,
                            services: 1,
                            service_ids: { $setIntersection: ['$services', '$$services'] }
                        }
                    },
                    { $match: { $expr: { $eq: ['$services', '$service_ids'] } } },
                    {
                        $project: {
                            service_ids: 0,
                            services: 0,
                        }
                    }
                ],
                as: "employees"
            }
        },

获取mongo集合中与交集数组中任何元素匹配的所有文档

1 个答案: