mongodb-query

问题 I have two collections in my mongodb database as follows: employee_details with approximately 330000 documents which has department_id as a reference from departments collection departments collections with 2 fields _id and dept_name I want to join the above two collections using department_id as foreign key by using lookup method. Join works fine but the mongo query execution takes long time when I add sort. Note: The execution is fast If I remove the sort object or If I remove the lookup

问题 I have two collections in my mongodb database as follows: employee_details with approximately 330000 documents which has department_id as a reference from departments collection departments collections with 2 fields _id and dept_name I want to join the above two collections using department_id as foreign key by using lookup method. Join works fine but the mongo query execution takes long time when I add sort. Note: The execution is fast If I remove the sort object or If I remove the lookup

问题 I have two different Arrays with Data and I have to merge two arrays same object in one object how can I merge with help of MongoDB Aggregation. here are my two Arrays {"ids" : [ { "_id" : ObjectId("5ba8d8dfaa988532967029af"), "level" : 2, "completed" : 5, "asset" : ObjectId("5ba8caa1aa98853296702989") }, { "_id" : ObjectId("5ba8d8dfaa988532967029b0"), "level" : 2, "completed" : 3, "asset" : ObjectId("5ba8caf6aa9885329670298a") }, { "_id" : ObjectId("5ba8d8dfaa988532967029b1"), "level" : 2,

问题 I have two different Arrays with Data and I have to merge two arrays same object in one object how can I merge with help of MongoDB Aggregation. here are my two Arrays {"ids" : [ { "_id" : ObjectId("5ba8d8dfaa988532967029af"), "level" : 2, "completed" : 5, "asset" : ObjectId("5ba8caa1aa98853296702989") }, { "_id" : ObjectId("5ba8d8dfaa988532967029b0"), "level" : 2, "completed" : 3, "asset" : ObjectId("5ba8caf6aa9885329670298a") }, { "_id" : ObjectId("5ba8d8dfaa988532967029b1"), "level" : 2,

问题 I have to store a tiff(tag image file format) or pdf scanned file in mongodb that should be Text search able . like if we want to search "on base of text" it should be able to search . I am going to use .net mvc or java with mongodb . so how can i store this pdf file and then can retrieve from database . any suggestion will be appreciated . thanks 回答1: You can store files by using MongoDb GridFs as described in this question and extract texts from a PDF file by using some features those

问题 I have this query db.words.find({ "$text": { "$search": "\"cake sale\"" } }) // gives expected answer in robo3T Now my text search is dynamic const text = "cake sale" db.words.find({ "$text": { "$search": `\\"${text}\\"` } }) But it does not give me expected output with nodejs. So How can I parse the backslash here? 回答1: Your query is incorrect. You need to change the query db.words.find({ "$text": { "$search": `"\"${text}\"` } }) to db.words.find({ "$text": { "$search": `\"${text}\"` } })

问题 I have this query db.words.find({ "$text": { "$search": "\"cake sale\"" } }) // gives expected answer in robo3T Now my text search is dynamic const text = "cake sale" db.words.find({ "$text": { "$search": `\\"${text}\\"` } }) But it does not give me expected output with nodejs. So How can I parse the backslash here? 回答1: Your query is incorrect. You need to change the query db.words.find({ "$text": { "$search": `"\"${text}\"` } }) to db.words.find({ "$text": { "$search": `\"${text}\"` } })

问题 I have the following Block which filters the data according to the filters I have applied; i.e. it should print only those data that match with "name" Block<Document> printBlock = new Block<Document>() { @Override public void apply(final Document document) { System.out.println(document.toJson()); } }; collection.find(eq("name", name)).forEach(printBlock); I wish to send this data from the current servlet to JSP so that I can display the data. How should I go about this? EDIT: JSP Page: <form

问题 I have the following Block which filters the data according to the filters I have applied; i.e. it should print only those data that match with "name" Block<Document> printBlock = new Block<Document>() { @Override public void apply(final Document document) { System.out.println(document.toJson()); } }; collection.find(eq("name", name)).forEach(printBlock); I wish to send this data from the current servlet to JSP so that I can display the data. How should I go about this? EDIT: JSP Page: <form

问题 I have the following Block which filters the data according to the filters I have applied; i.e. it should print only those data that match with "name" Block<Document> printBlock = new Block<Document>() { @Override public void apply(final Document document) { System.out.println(document.toJson()); } }; collection.find(eq("name", name)).forEach(printBlock); I wish to send this data from the current servlet to JSP so that I can display the data. How should I go about this? EDIT: JSP Page: <form