mongodb 3 4

seconds to kill. By this example, I believe you have a sensory understanding of the index. Three: Unique index As with SQL Server, you can create a unique index, and duplicate key values cannot be inserted naturally, and the use in MongoDB is as follows: Db.person.ensureIndex ({"Name": 1},{"unique": true}). Four: Combined index Sometimes our query is not single-condition, may be multi-conditional, such as looking for the "1989-

Tags: www RDBMS equals closed blog alt start EXE 2.0 "Note: MongoDB automatically sets the _id field as the primary key" --------------------------------------------------------------------------------------------------------------- -----------------------------------------------------------------------------------> Don't say a word, just start knocking at the command! "Note 1:mongodb command end do not hi

Label:Because the project to use MongoDB, today tried to build a bit. First MONGO is still very good, yum or manual download, I am the most recent version of Yum installed 3.0.4. Basically, after the installation is complete, a GUI management tool needs to be installed, and I have tried a lot, all the same. Finally, choose to use Robomongo because this GUI tool has versions on Linux, MAC, and Windows. I install it on CentOS and then modify the/etc/mon

": [ { "role": "Useradminanydatabase", "DB" : "Admin" } ] } The above is the command to execute: User: Username PWD: Password Roles: Specifies the role of the user, an empty array can be used to set the null role for the new user; In the Roles field, you can specify built-in roles and user-defined roles. Roles in role can be selected: Built-in Roles (built-in role): 1. Database user role: Read, readWrite; 2. Database management roles: DbAdmi

connection, and the single line is A virtual connection.Note: The chain synchronization structure of MongoDB is similar to the streaming replication of data blocks in HDFS in Hadoop. This can greatly reduce the pressure on the master node and improve the speed of data synchronization.3. New Functions The above is the internal implementation of current Replica Sets synchronization, and some new features wil

= "POST"> Divclass= "Fuzq_input_wrap"> label for="">User name:label> inputtype= "text"ID= "username"name= "username"Autofocus=""Required="" /> Div> Divclass= "Fuzq_input_wrap"> label for="">Password:label> inputtype= "Password"ID= "Password"name= "Password"Required="" /> Div> Divclass= "Fuzq_btn_wrap"> Buttontype= "Submit">SubmitButton> Div> Divc

Recently installed mongodb3.1.4, and enabled the authorization authentication, in DOS window operation without any problems, in order to maintain the convenience of downloading a client tool Robomongo 0.8.5, user name, password and other configuration good click Test, the result of connection service is not a problem, permission verification did not pass , as shown in the log, found a sentence: Failed to authenticate admin@admin with mechanism mongodb

, add Shard server (allowlocal allows multiple shards to be deployed on-premises, not allowed by default) Use admin db.runcommand ({addshard: "192.168.24.42:27017", allowlocal:true}) Db.runcommand ({addshard: " 192.168.24.252:27017 ", allowlocal:true}) //Log on to the MONGOs server, turn on the database sharding feature, and specify the Shard key of the collection Db.runcommand ({ Enablesharding: "DBName"}) Db.runcommand ({shardcollection: "Dbname.cname", Key:{fieldname:1}})

Admindb.changeuserpassword ("username", "xxx")7. View user InformationDb.runcommand ({usersinfo: "UserName"})8. Change Password and user informationDb.runcommand ( { updateUser: "username", pwd: "xxx", customdata:{title: "xxx"} )Note:1. and user management related operations are basically to run under the Admin database, to use the admin first;2. If under a single database, it can only operate on the permissions of the current database;3.

role for the new user; In the Roles field, you can specify built-in roles and user-defined roles. Roles in role can be selected: Built-in Roles (built-in role): 1. Database user role: Read, readWrite; 2. Database management roles: DbAdmin, Dbowner, Useradmin; 3. Cluster Management role: Clusteradmin, Clustermanager, Clustermonitor, Hostmanager; 4. Backup Restore role: backups, restore;

nested document (equivalent to a one-to-many relationship)MongoDB Syntax:. Save ({ID: ' 2015040013 ', Name: ' New partner sourcing process ', Dept: ' Management department ', DETAIL:[{WF: ' Wfname: ' Start '},{WF: ' "' wfname '), ' End '} ')SOAP Requests:(3) Modify the data, in the case of the _id value is unchanged, to perform the modification operationMongoDB Syntax:. Save ({"_id": {"$oid": "5525d9e084ae

Label:Preface: Daughter-in-law asked to be sent up. I want the first page of this article. 1,nuget introduced MongoDB. Then the namespace Using Mongodb.bson; Using Mongodb.driver; Using MongoDB.Driver.Builders; Using MongoDB.Driver.Linq; 2, Global Declaration Mongodatabase MONGO = new Mongoclient (configurationmanager.appsettings["Psconnstrmongodb"]). Getserver (). Getdatabase ("Psnew"); Mongocollection arts = NULL;

TopicThe 2-3-4 tree is a special case of B-trees and is a B-tree with a degree of 2. In the B-tree blog, we implement the B-tree is a template, so to get the 2-3-4 tree, that is, the degree of 2 B-tree is very easy, as long as the declaration can be--btreeIn the subject, to achieve is the 2-

Topic 2-3-4 Tree is a special case of B-tree, it is a B-tree with degrees 2. In the B-tree blog, we implemented the B-tree is a template, so to get the 2-3-4 tree, the degree of 2 B-tree is very easy, as long as the declaration can be--btree In this subject, to achieve is the 2-3