我想找到products并為每個產品附加deals它。A來自同deal一個product集合，但基于一些共同的屬性。因此，根據我的要求，管道應該回傳檔案，為每個檔案找到與當前不同但具有相同detail.duration. 但即使我有許多具有相同持續時間的檔案，deals總是[]. 你能找出我的管道的問題嗎？
以下是我正在運行的聚合管道：為了清楚起見，我添加了過濾器 _id $in，基于下面顯示的檔案。這不是真正的管道 $match 查詢的一部分。
db.products
.aggregate([
{
$match: {
_id: {
$in: [
ObjectId("6210fa8746bee3fcbd0ad062"),
ObjectId("6210fa7c46bee3fcbd0acc21"),
],
},
"detail.duration": { $gt: 0 },
},
},
{
$lookup: {
from: "products",
let: { id: "$_id", duration: "$detail.duration" },
as: "deals",
pipeline: [
{
$match: {
_id: { $ne: "$id" },
"detail.duration": "$duration",
},
},
{ $project: { detail: 1 } },
{ $limit: 1 },
],
},
},
{ $limit: 2 },
{ $project: { deals: 1 } },
])
.pretty();
結果是這樣的：
{ "_id" : ObjectId("6210fa7c46bee3fcbd0acc21"), "deals" : [ ] }
{ "_id" : ObjectId("6210fa8746bee3fcbd0ad062"), "deals" : [ ] }
以下是集合中的兩個示例檔案：
{
"_id" : ObjectId("6210fa8746bee3fcbd0ad062"),
"book" : "https://wegotrip.com/en/paris-d3/muse-d-orsay-and-musee-de-l-orangerie-combined-tour-ticket-p1117/?SUB_ID=336264",
"address" : "Rue de Lille, 62bis",
"countryName" : "France",
"cityName" : "Paris",
"location" : {
"lang" : 48.859886,
"lat" : 2.3254821,
"country" : ObjectId("6210fa7746bee3fcbd0aca20"),
"city" : ObjectId("6210fa7746bee3fcbd0aca1c"),
"location" : "Rue de Lille, 62bis",
"_id" : ObjectId("6210fa8746bee3fcbd0ad063")
},
"includes" : [
{
"value" : "Skip-the-line ticket to Orsay Museum",
"included" : true
},
{
"value" : "Skip-the-line ticket to the Musée de l'Orangerie",
"included" : true
},
{
"value" : "Detailed description of the Nymphéas from Claude Monet",
"included" : true
},
{
"value" : "Interesting stories of many great artists and their lives",
"included" : true
},
{
"value" : "An easy walkthrough of the Musée d'Orsay and the Musée de l'Orangerie and their great collection",
"included" : true
},
{
"value" : "Headphones — you should bring your own",
"included" : false
}
],
"price" : {
"priceConcession" : null,
"priceChild" : null,
"price" : 57,
"currency" : ObjectId("6210fa7746bee3fcbd0aca2f"),
"_id" : ObjectId("6210fa8746bee3fcbd0ad064")
},
"detail" : {
"isPass" : false,
"features" : [
{
"key" : "audio_guide",
"value" : "Audio Guide"
}
],
"highlights" : [
"Admire the masterpieces by Monet, Renoir, Degas, Cézanne, and many more",
"Discover one of the finest collections of Impressionist art in the world",
"Visit the Nymphéas by Monet, one of the greatest pieces of Impressionism",
"Explore the Guillaume and Walter collection and find out what makes it unique"
],
"details" : [ ],
"images" : [
{
"id" : 7270,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/1117/dsc04800/01d0770dcc0cac4c6de0f6eae70742f6.jpg",
"full" : "https://app.wegotrip.com/media/store/1117/dsc04800.jpg"
},
{
"id" : 7269,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/1117/nympheasannees30salle1parisiennephotorogerviolet/e1270aef1c01391290df71d1f83c8abc.jpg",
"full" : "https://app.wegotrip.com/media/store/1117/nympheasannees30salle1parisiennephotorogerviolet.jpg"
},
{
"id" : 7268,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/1117/ob1f7c80dsc02414-large/7712cb29e133ee3acb4b2bffbc2ac654.jpg",
"full" : "https://app.wegotrip.com/media/store/1117/ob1f7c80dsc02414-large.jpg"
},
{
"id" : 7267,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/1117/tuileriesgardensb16dsc00678talrg/47430ab8a257e3ccd2337d7a0d750c57.jpg",
"full" : "https://app.wegotrip.com/media/store/1117/tuileriesgardensb16dsc00678talrg.jpg"
},
{
"id" : 7266,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/1117/009/54223ef27aac5cd94fe5c20893abf2de.jpg",
"full" : "https://app.wegotrip.com/media/store/1117/009.jpg"
},
{
"id" : 7264,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/1117/monet-morning-with-weeping-willow/09bf842cc9a9d7eade8d0739f704699f.jpg",
"full" : "https://app.wegotrip.com/media/store/1117/monet-morning-with-weeping-willow.jpg"
}
],
"duration" : 2,
"_id" : ObjectId("6210fa8746bee3fcbd0ad065")
},
"availability" : null,
"subcategory" : [
{
"id" : 6,
"title" : "Sightseeing Tickets & Passes",
"slug" : "sightseeing-tickets-passes"
}
],
"category" : [
{
"id" : 6,
"title" : "Sightseeing Tickets & Passes",
"slug" : "sightseeing-tickets-passes"
}
],
"type" : "Audio Guide",
"description" : "Visit the famous Musee d'Orsay and Musée de l'Orangerie in Paris with this combined self-guided tour! \r\n\r\nNavigate through the maze of exhibition rooms with mobile app and see a collection of works by the Impressionists and Expressionists – Seurat, Cezanne, Gaugin, Monet, Renoir, Manet, Van Gogh, Degas; sculptors like Rodin, Pompon and others. Check out a mini-version of the Statue of Liberty! \r\n\r\nExplore the Nymphéas paintings by Claude Monet, that is called \"the Sistine chapel of Impressionism\". Admire the great works of Picasso, Soutine, Rousseau, Matisse and many others part of the Paul Guillaume and Jean Walter collection. Learn about the style and private life of the artists.\r\n\r\nThe audio-guide will provide you with all the information on the cultural significance of these paintings. Walking through rooms you will understand how revolutionary for those times Manet’s, Cezanne’s and Degas’ creation really was casting doubts on conservative, academic conceptions of 'true art' and offering new techniques and ideas.",
"thumbnail" : "https://app.wegotrip.com/media/CACHE/images/store/1117/013/c0b8cce52cb61ab1f30872e6e93385b4.jpg",
"name" : "Musée d'Orsay/Musée de l'Orangerie Combined Admission Ticket & Audio Tour",
"attractionDescription" : "",
"attractionName" : "Musée d'Orsay & Musée de l'Orangerie",
"attraction" : ObjectId("6210fa8746bee3fcbd0ad056"),
"provider" : {
"rating" : {
"count" : 0,
"average" : null,
"_id" : ObjectId("6210fa8746bee3fcbd0ad067")
},
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/1117/013/c0b8cce52cb61ab1f30872e6e93385b4.jpg",
"slug" : "muse-d-orsay-and-musee-de-l-orangerie-combined-tour-ticket",
"id" : "1117",
"key" : "1",
"_id" : ObjectId("6210fa8746bee3fcbd0ad066")
},
"__v" : 0
}
{
"_id" : ObjectId("6210fa7c46bee3fcbd0acc21"),
"book" : "https://wegotrip.com/en/barcelona-d1/the-dali-museum-in-figueres-p3/?SUB_ID=336264",
"address" : "Pujada del Castell, 43",
"countryName" : "Spain",
"cityName" : "Barcelona",
"location" : {
"lang" : 42.26829425831263,
"lat" : 2.95884132385254,
"country" : ObjectId("6210fa7746bee3fcbd0aca3e"),
"city" : ObjectId("6210fa7746bee3fcbd0aca3a"),
"location" : "Pujada del Castell, 43",
"_id" : ObjectId("6210fa7c46bee3fcbd0acc22")
},
"includes" : [
{
"value" : "Recommendations of places to visit to understand the life of Dali better",
"included" : true
},
{
"value" : "Skip-the-line ticket to Dali Theatre-Museum",
"included" : true
},
{
"value" : "Headphones — you should bring your own",
"included" : false
}
],
"price" : {
"priceConcession" : null,
"priceChild" : null,
"price" : 33,
"currency" : ObjectId("6210fa7746bee3fcbd0aca2f"),
"_id" : ObjectId("6210fa7c46bee3fcbd0acc23")
},
"detail" : {
"isPass" : false,
"features" : [
{
"key" : "audio_guide",
"value" : "Audio Guide"
}
],
"highlights" : [
"Discover Dali's surrealism starting with the building of the museum — it's definitely one of a kind",
"Inside the museum you'll find the most famous and controversial works of the artist",
"Our tour will provide you with insights and exiting facts about Dali's works"
],
"details" : [ ],
"images" : [
{
"id" : 6916,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/3/figueres-oleguer2/032b55c27bb2cd119bdc7fe6c4b86491.jpeg",
"full" : "https://app.wegotrip.com/media/store/3/figueres-oleguer2.jpeg"
},
{
"id" : 6915,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/3/sky-monument-statue-golden-museum-yellow-1156442-pxherecom/28c645449a9f45ec1e8ede7b7ffbe30f.jpg",
"full" : "https://app.wegotrip.com/media/store/3/sky-monument-statue-golden-museum-yellow-1156442-pxherecom.jpg"
},
{
"id" : 6914,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/3/architecture-window-museum-landmark-surrealism-catalonia-800928-pxherecom/43691ba6aecc2ee084c300c150e32a03.jpg",
"full" : "https://app.wegotrip.com/media/store/3/architecture-window-museum-landmark-surrealism-catalonia-800928-pxherecom.jpg"
},
{
"id" : 831,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/3/figueres-oleguers3k6yoz/b9c3093c79cf50e621e022706af59ad6.jpg",
"full" : "https://app.wegotrip.com/media/store/3/figueres-oleguers3k6yoz.jpg"
},
{
"id" : 832,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/3/shutterstock82210018/2a2450d4f75edf4549d36f2286b6f19b.jpg",
"full" : "https://app.wegotrip.com/media/store/3/shutterstock82210018.jpg"
},
{
"id" : 833,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/3/dali-museum-8983261920/aa0d93e475c7b7388bee88ff14f8d795.jpg",
"full" : "https://app.wegotrip.com/media/store/3/dali-museum-8983261920.jpg"
},
{
"id" : 834,
"description" : "",
"cover" : false,
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/3/shutterstock196896461/74fc427d0a27f0aa199ed24f4c51bcc5.jpg",
"full" : "https://app.wegotrip.com/media/store/3/shutterstock196896461.jpg"
}
],
"duration" : 2,
"_id" : ObjectId("6210fa7c46bee3fcbd0acc24")
},
"availability" : null,
"subcategory" : [
{
"id" : 3,
"title" : "Theme Tours",
"slug" : "theme-tours"
},
{
"id" : 1,
"title" : "Culture & History",
"slug" : "culture-and-history"
},
{
"id" : 6,
"title" : "Sightseeing Tickets & Passes",
"slug" : "sightseeing-tickets-passes"
}
],
"category" : [
{
"id" : 3,
"title" : "Theme Tours",
"slug" : "theme-tours"
},
{
"id" : 1,
"title" : "Culture & History",
"slug" : "culture-and-history"
},
{
"id" : 6,
"title" : "Sightseeing Tickets & Passes",
"slug" : "sightseeing-tickets-passes"
}
],
"type" : "Audio Guide",
"description" : "The Dalí Theatre and Museum is a museum of the artist Salvador Dalí in his home town of Figueres, in Catalonia, Spain. Dalí is buried there in a crypt below the stage. \r\n\r\nImmerse yourself in an exciting journey through the world of the genius of surrealism. Reveal the meaning of his ambiguous creations and learn the history of the artist's life. Enjoy the unique world of Dali in this excursion.",
"thumbnail" : "https://app.wegotrip.com/media/CACHE/images/store/001_Ispaniya_Figeras_Teatr-01/783c3a10c34eb40c29f14f704cd9c8d1.jpeg",
"name" : "The Dali Theatre-Museum: Skip-the-Line & Audio Tour",
"attractionDescription" : "",
"attractionName" : "Dali Theatre and Museum",
"attraction" : ObjectId("6210fa7c46bee3fcbd0acc15"),
"provider" : {
"rating" : {
"count" : 0,
"average" : null,
"_id" : ObjectId("6210fa7c46bee3fcbd0acc26")
},
"preview" : "https://app.wegotrip.com/media/CACHE/images/store/001_Ispaniya_Figeras_Teatr-01/783c3a10c34eb40c29f14f704cd9c8d1.jpeg",
"slug" : "the-dali-museum-in-figueres",
"id" : "3",
"key" : "1",
"_id" : ObjectId("6210fa7c46bee3fcbd0acc25")
},
"__v" : 0
}
以上兩個都detail.duration設定為2并且根據查詢，這兩個應該相互視為交易并在結果檔案中找到，但查詢回傳deals: []一個空陣列。我無法弄清楚問題所在。
uj5u.com熱心網友回復：
從$match（限制）
$match 查詢語法與讀操作查詢語法相同；即 $match 不接受原始聚合運算式。要在 $match 中包含聚合運算式，請使用 $expr 查詢運算式。
而你需要用來$$獲取變數值。
讓
要在管道階段參考變數，請使用“$$”語法。
$match將管道中的階段更改為：
{
$match: {
_id: {
$ne: "$$id"
},
$expr: {
$eq: [
"$detail.duration",
"$$duration"
]
}
}
}
示例 Mongo Playground
轉載請註明出處，本文鏈接：https://www.uj5u.com/ruanti/430449.html