mongodb shell tutorial

1. Shell Connection using MongoDB:Start Mongodb:mongod--dbpath d:\mongoDB\dbOpen new shell, connect Mongodb:mongo 2. Shell Basic Command:MongoDB command-line OperationsView all databases: Show DBSUsing a database: Use MyDBView all collections: Show CollectionsView all elements of a collection: Db.mycollection.fin

Label:MongoDB is a very popular NoSQL database management system, officially: MongoDB, I installed in localhost is the Enterprise Server version, the default installation file directory is: C:\Program files\mongodb\server\3.2\bin, click Windows+r, enter cmd, start command Prompt, go to the installation directory Every time you open command prompt you need to enter the installation directory of

Client Support for MongoDB As a very mature NoSQL database, MONGDB support for a variety of programming languages has been very perfect, and now support the major mainstream programming languages include:1,mongo Shell2,python3,java4,c#5,node.js6,c++ In these languages, the simplest, most lightweight of the MONGO shell, without any other dependent environment, only need a MONGO client, you can connect the l

10) db.char.find ({' name ': ' Weixiaobao '}). Skip (2). Limit (10)f) The query returns the number of bars Db.char.find ({' name ': ' Weixiaobao '}). Count ()g) sort (by name ascending, age descending) Db.char.find (). Sort ({' name ': 1, ' age ':-1})h) Query the specified column to db.char.distinct (' name ')i) Remove the set Db.char.drop ()j) Create index Db.char.ensureIndex ({' Name ': 1, ' Age ': 1},{unique:true})k) View index db.char.getIndexes ()L) Delete index Db.char.dropIndex (' IndexN

"}}]) $last Gets the final document from the source document according to the grouping. Usually, this makes sense, along with some previous applications such as "$sort"-stage. Db.mycol.aggregate ([{$group: {_id: "$by _user", Last_url: {$last: "$url"}}]) Piping ConceptsThe UNIX command shell pipeline refers to the possibility of some inputs and outputs performing operations as input to the next command. The

MongoDB installation tutorial and simple operations in Ubuntu1 MongoDB First, let's start with a simple definition of MangoDB: MongoDB is a distributed file storage-based database. Written in C ++. It is designed to provide scalable, high-performance data storage solutions for WEB applications.MongoDB is a product betw

MongoDB shell obtains the maximum and minimum values. mongodbshell MongoDB does not find a dedicated method to calculate the maximum value, but it can be replaced by sorting and getting the first one. The following collection data is as follows: { "_id" : ObjectId("54c39358acace71b1bd20a70"), "epoch_min" : NumberLong(1422030840), "usage_ratio" : 0.03514000773429

A new requirement was received in the previous two days to monitor the maximum number of MongoDB connections, memory usage, etc. in the Linux shell script. But I do not understand the Linux Shel, just a few simple common Linux operations, as long as a wild search, and finally many attempts to finally get these values. The steps for success are as follows: 0, Write a line of data that

variable P to modify the first record Db.persons.update (p,{name: "uspcat000"}) Db.perons.findOne () adds a field to an existing record. MONGO can arbitrarily increase any type of field in a record First , modify the value of the first record to age=1 Db.persons.update (P,{age:1}) and then update Db.persons.update ({age:1},{$set: {name: "Hello.world"}}) The above code means that when the first reco

The shell command operation syntax is similar to that of JavaScript. In fact, the underlying query statements on the console are all completed using JavaScript scripts. Run the shell command to start cmd.exe. Common shell commands are as follows: 1. query the names of all local databases > show dbs; 2. Switch to the specified database environment (if no databa

Tags: io os using SP file data on CTI ADLimit () methodTo limit the records in MongoDB, you need to use the limit () method. The limit () method accepts a numeric parameter, which is the number of documents to display.Grammar:The basic syntax for the limit () method is as follows>db. Collection_name. Find(). Limit(number) ExampleConsider the collection Myycol with the following data{ "_ID" : ObjectId(5983548781331adf45ec5), "Title":"

Common shell for mongodb and mongodbshell > Use cmd_test // create a database Switched to db pai_test > Db. createCollection ("test") // create a table as a set. {"OK": 1} > Db. Db. addUser (db. group ( Db. adminCommand (db. groupcmd ( Db. auth (db. groupeval ( Db. changeUserPassword (db. hasOwnProperty ( Db. cloneCollection (db. help ( Db. cloneDatabase (db. hostInfo ( Db. commandHelp (db. isMaster ( Db. c

{} Specifies that those columns are displayed and not displayed (0 means that 1 is not displayed). Query showing 2nd, 3 document data The default parameter for the Skip () method is 0. Skip and limit combine to achieve paging. sorting Sort () methodIndex Ensureindex () method Multiple field indexes:db.student.ensureIndex({"name":1,"hobby":-1}) Polymerization aggregate ()Only one method is used here, grouped and counted,

Implementation tutorial of MongoDB set field matching query method, mongodb Field MongoDB is a distributed file storage-based database. This article describes how to perform matching queries on the fields integrated in MongoDB records.1. Create a Test Database use testdbdb.

Cakephp and mongodb integration tutorial. If you do not have a mongodb testing environment, you can install a mongodb service locally. here is a graphic installation tutorial for mongodb in windows. By default, the

and findAndModify Functions RunCommand can execute special functions in mongoDB. FindAndModify is one of the special functions. It is used to return the document after update or remove. RunCommand ({"findAndModify": "processes ", Query: {queryer }, Sort {sort }, New: true Update: {Updater }, Remove: true }). Value Ps = db. runCommand ({ "FindAndModify": "persons ", "Query": {"name": "text "}, "Update": {"$ set": {"email": "1221 "}}, "New": true }). V

Turn from: http://hi.baidu.com/zwfec/item/3cfecfabafda3a258819d38b Today, look at the server, found that Mongod start not up, prompted Sun June 2 12:27:02 error:couldn ' t connect to server 127.0.0.1:27017 src/mongo/shell/mongo.js:91 Error Look up the solution on the Internet, most people say set up dbpath, this is to solve the problem, but not to find the root cause of the problem, The root of the problem is that the machine illegal shutdown caus

Shell operations on mongodb and shellmongodb Want to query MongoDB data through shell Many people on the Internet say that mongoDB does not support shell. I basically agree with this statement; But the project needs to be done,

Dropdatabase () methodThe MongoDB db.dropdatabase () command is used to delete an existing database.Grammar:The basic syntax for the dropdatabase () command is as follows:DB. Dropdatabase() This will delete the selected database. If you have not selected any databases, then it will delete the default ' test ' databaseExample:First, check the list database by using the command show DBS>Show dbslocal 0.78125GB0.23012GB0.23012GB> If you want t

," nmodified ": 1}) 2.3. Deleting documentsMongoDB removes the document from the collection with remove ()FormatDb. Collection_name.remove (Delletion_critteria,justone)Justone if set to TRUE or 1, only one document is deleted.ExampleDelete the document named ' User1 ' before deleting the document that exists in the collection "user" before querying all documents after deletion to determine if the deletion was successful> Db.user.find () {"_id": ObjectId ("58e1d2f0bb1bbc3245fa754b"), "name": "L