aggregation-framework

问题 I have a data like below in my mongoDB collection. I want to count the total number or search_term on today basis. _id:ObjectId("5b7e1d38981cdc1a7c8bb5fc") search_term:"Baiyoke Boutique" date:"August 23rd 2018, 9:34:32 am" _id:ObjectId("5b7e1fa8fa27fd2754080ad9") search_term:"Baiyoke Boutique" date:"August 23rd 2018, 9:44:56 am" _id:ObjectId("5b7e28314d2d0f388c1596cd") search_term:"Baiyoke Florting Market" date:"August 23rd 2018, 10:21:21 am" I have tried following query. I have used moment.

问题 I'm building a new LMS in mongodb and I have the following collections: Courses { "_id": ObjectId("5f6a6b159de1304fb885b194"), "title": "Course test", "sections": [ { "_id": ObjectId("5f6a6b159de1304fb885b195"), "title": "Section 1 - introduction", "order": 1, "modules": [ { "_id": ObjectId("5f6a6b159de1304fb885b196"), "module_FK_id": ObjectId("5f6a6b149de1304fb885b135"), "title": "Module 1", "order": 1 }, { "_id": ObjectId("5f6a6b159de1304fb885b198"), "module_FK_id": ObjectId(

问题 Having this document structure in MongoDB : { "_id":<MongoDBID>, "chatUser1ID": 2, "chatUser2ID": 3 } Now i want to get all chat partners from Mongo where the Chat Partner with the ID 2 is included in either "chatUser1" or "chatUser2". For that i want to use the $match and $group function. $chatUserID = $_POST["chatUserID"]; // 2 in my example $chatCursor = $chatCollection->aggregate([ [ '$match' => [ '$or' => [ ["chatUser1ID" => $chatUserID], ["chatUser2ID" => $chatUserID] ] ] ] ,[ '$group'

问题 I have a mongodb aggregation $reduce pipleine that is not working as expected. This is what I am trying to achieve. Basically I am trying to get the object with the highest value in a given property. In some objects $reduce returns the wrong object in others it returns null , meaning no object satisfied the condition. My code has the group stage and other stage that produce the variable used in the $reduce stage. Are there any known preceding stages in the aggregation pipeline that might be

问题 I have a mongodb aggregation $reduce pipleine that is not working as expected. This is what I am trying to achieve. Basically I am trying to get the object with the highest value in a given property. In some objects $reduce returns the wrong object in others it returns null , meaning no object satisfied the condition. My code has the group stage and other stage that produce the variable used in the $reduce stage. Are there any known preceding stages in the aggregation pipeline that might be

问题 I have a mongodb aggregation $reduce pipleine that is not working as expected. This is what I am trying to achieve. Basically I am trying to get the object with the highest value in a given property. In some objects $reduce returns the wrong object in others it returns null , meaning no object satisfied the condition. My code has the group stage and other stage that produce the variable used in the $reduce stage. Are there any known preceding stages in the aggregation pipeline that might be

问题 I have a mongodb aggregation $reduce pipleine that is not working as expected. This is what I am trying to achieve. Basically I am trying to get the object with the highest value in a given property. In some objects $reduce returns the wrong object in others it returns null , meaning no object satisfied the condition. My code has the group stage and other stage that produce the variable used in the $reduce stage. Are there any known preceding stages in the aggregation pipeline that might be

问题 This question is a continuation from this question. Let's say I have this data [ {id:0, points:-9, rank:true} {id:1, points:-49, rank:true} {id:2, points:9, rank:false} {id:3, points:-24, rank:false} {id:4, points:3, rank:true} ] I want to get the object with the highest points and rank is equal to positive and add the property winner:true So in this case the object with id:4 . How can I achieve the same in MongoDB aggregation without using $reduce ? 回答1: You can try, $match rank is positive

问题 This question is a continuation from this question. Let's say I have this data [ {id:0, points:-9, rank:true} {id:1, points:-49, rank:true} {id:2, points:9, rank:false} {id:3, points:-24, rank:false} {id:4, points:3, rank:true} ] I want to get the object with the highest points and rank is equal to positive and add the property winner:true So in this case the object with id:4 . How can I achieve the same in MongoDB aggregation without using $reduce ? 回答1: You can try, $match rank is positive

问题 I have these three collections (Products, Users & Comments) 1. Product Model var ProductSchema = new Schema({ title: { type: String, text: true, required: true }, description: { type: String, required: true }, category: [{ type: String, required: true }], type: [{ type: String, required: true }], isUsed: { type: Boolean, }, manufacturer: { type: String }, price: { type: Number }, }); 2. User Model var UserSchema = new Schema({ firstName: { type: String, text: true, required: true }, lastName: