mongodb compass run query

field, and just the bo NUS field in the documents in the points array. The _id field is returned by default.Db.users.find ({status: "A"}, {name:1, status:1, "Points.bonus": 1})The operation returns the following documents:{"_id": 2, "name": "Bob", "status": "A", "points": [{"Bonus": $}, {"Bonus": 12}]} {"_id": 3, "name": "Ahn", "status": "A", "points": [{"Bonus": 8}, {"Bonus": 20}]} {"_id": 6, "name": "abc", "Status": "A", "points": [{"Bonus": 8}, {"Bonus": 7}]}Project specific array Elements i

result of the query is a consistent snapshot at the moment the query executes. This will also be mentioned later. "Get consistent results" When we get the data from the MongoDB, we usually do this: once the document is processed, it is immediately updated to the database. There is a problem with a large number of documents, and let me describe: As mentioned earl

-- ===========================--MongoDB Slow query log-- =========================== reference:http://docs.mongodb.org/manual/tutorial/manage-the-database-profiler/ Profiling levels:1 Resume0-the Profiler is off, does does not collect any data.1-collects profiling data for slow operations only. By default slow operations are those slower than.You can modify the ' threshold for ' slow ' operations with the S

MongoDB paging query method and Performance I have been a little busy recently. There are a lot of things to summarize. In fact, there should be four, five, and six Redis series... however, Redis in Action has not been completed yet. I will summarize it later. Otherwise, it will be too watery. Sorry, readers. Since the last time in Redis, it was a bit of an entry into Nosql products. This will change the di

convert each document from BSON to a JavaScript Object and run it through the $ where expression. This process cannot use indexes, so the query speed is much slower than the regular query speed. If necessary, you can use the regular query as the pre-filter. If you can use the index, you can use the index to filter acc

document arrays.As shown in the MongoDB document structure:The advantages of using a document database are as follows:In many programming languages, documents (that is, objects) fit into the native data type;Embedded documents and arrays reduce the need for expensive relationship-related associations;Dynamic Data structure mode supports smooth, scalable polymorphism.InstallationOfficial website: http://www.mongodb.org/downloads, download the Windows

test set below, only the operation of the collection is valid, if necessary for the entire instance to be valid, you need to set in all sets or open the parameters when opening2 The result returned to you after each set is the state (including the level, time parameter) before the change.2: Not through MONGO Shell:At the time of MongoDB startupMongod--profile=1--slowms=200or add 2 lines to the configuration file:Profile = 1SLOWMS = 2003: Close Profil

("cust_id")]Public string CustomerId {get; set ;}/// /// Total/// [BsonElement ("amount")]Public int Amount {get; set ;}/// /// Status/// [BsonElement ("status")]Public string Status {get; set ;}} For the following operations based on the MongoDB GUI tool, see references 3.First, let's take a look at the parameters and results required for paging. The common parameters required for paging are:PageIndex current pageP

. $cmd. FindOne ({"Drop": "Refactor"})When the MongoDB server gets a request to query the $cmd collection, it starts a set of special logic to handle, rather than handing it over to the normal query code.Almost all MongoDB drivers provide a runcommand-like Help method to execute commands, and if necessary, you can use

questions about this time, no way, MONGO. Habit is good. *//* The above line of queries is a combination query for Regist_date, indicating that all users registered from 2013-1-1 to 2013-1-31 are queried */ The next query method is more complicated.Regular expressions, MONGO do not have similar SQL-like features, but you can use regular expressions insteadThere are two cases of using regular expression que

Method)Atsun.reflect.NativeConstructorAccessorImpl.newInstance (Unknown Source)Atsun.reflect.DelegatingConstructorAccessorImpl.newInstance (Unknown Source)Atjava.lang.reflect.Constructor.newInstance (Unknown Source)Atorg.springframework.beans.BeanUtils.instantiateClass (beanutils.java:148)... 29moreStep Two: Implement: Privatemorphia Morphia; Public Ordersdaoimpl () {morphia= new Morphia (); Morphia.map (Orders.class); } @Override Public Pagemodelwhen we start to

version, but also for the statistics of the data brought convenience. 3. MongoDB loads the data in the database into memory as a file map after it is started. If the memory resources are quite rich, this will greatly improve the query speed of the database, after all, memory I/O efficiency is much higher than disk. However, as a fresh transaction,

Common query indexes of mongoDB (III)1. _ id index is the default index created by the vast majority of sets. For each inserted data, MongoDB automatically generates a unique _ id field. > Db. jerome_2.collection.insert ({x: 2}) WriteResult ({"nInserted": 1})> db. jerome_2.collection.getIndexes () [{"v": 1, "key": {"_ id": 1}, "name": "_ id _", "ns ": "jerome. je

MongoDB Query Find(2012-01-05 11:38:10)reproduced Tags:it Category: MongoDB MongoDB Query FindSpecifies the key to return, specifying the desired key through the second parameter of Find or FindOne.> db.visithomepage.find ({},{"user_i

Tags: UI directory lin rdl hat enqueued Tor it comes withThere is a need: tracking MongoDB SQL statements and slow query collection Step one: Use the MongoDB self-function to see how many DML statements have been run over a period of time. Run under the bin directory./mongos

Node. js operates the mongodb addition, deletion, modification, and query function instance, nodejsmongodb This article describes the addition, deletion, modification, and query functions of node. js operations on mongodb. We will share this with you for your reference. The details are as follows: Install related modul

After a short essay, the installation of MongoDB can be done after the most basic database operation, the following steps to achieve your Hello world!1. Open terminal Execution Brew services start MongoDB start MongoDB service, execute MONGO open shell operation;2. Show All DB: show dbs3. Enable a DB: Use mydb (if no mydb will automatically create this library)4.