MongoDB

Two years ago the use of MongoDB, has not had the opportunity to use again, the most recent company made a cloud print small ticket service platform, data storage and is stored through MongoDB, through this opportunity to record their own

1. Turn on MongoDB service 1 sudo service MongoDB start2. Enter the MongoDB command line interface to exit at the command line by knocking exit 1 MONGO3.find () Basic query usage: DB. Collection_name.find ();--(the concept of a set collections in

1. First to the official website (mongodb) Download the appropriate installation package, the latest version is 3.0.4My computer is Win7 system 64-bit, download Windows 64-bit r2+ version, download completed after installation to the D:\MongoDB

Official documents:http://docs.mongodb.org/manual/replication/Replication sets multiple servers maintain the same copy of dataHow to use the replication set first stepStart Mongod is to specify the replica set name, either by adding –replset name or

Enable authenticationMongod boot is not enabled by default, you need to specify –auth boot, or set Security.authorization to "enabled" in the configuration fileCreate userDb.createuser (user, Writeconcern) Document

As with MySQL, Oracle, the first thing to download is the driver package.Open MyEclipse and create a Java project.Create a Lib folder under the project, place the downloaded driver into Lib and build to path:Then build a db.properties file under

The recent period of time for MongoDB has been a simple learning from what is it? Do? How to use it? Advantages and Disadvantages This series of questions is now simple to use, and I would like to have a brief summary and summary of it, then this

1: See what is currently being done by MongoDB?Db.currentop () is equivalent to: db. $cmd. Sys.inprog.findOne ()　　2: Detailed Currentop ()Gechongrepl:primary> Db.currentop () {"InProg": [{"Opid": 6222, "active": true, "secs_running": 3,

From the MongoDB phased technical summary to extract and collate the 10 points that are helpful to everyone:1.mongodb table names and field names are unified in lowercase lettersMongoDB is the default case-sensitive, in order to avoid the previous

1:oplog IntroductionOplog is a fixed collection under the local library, and secondary is copied by looking at the primary Oplog collection. Each node has a oplog that records the information that is copied from the primary node so that each member

Environment Description: MongoDB 2.4.10-2.6.61. Start with daemon configuration fileMongod-f/etc/mongodb.conf2. Join the Boot startup itemecho "Mongod-f/etc/mongodb.conf;" >>/etc/rc.localIf the boot entry is not valid, please refer to the link: http:

Hibernate (Object-Oriented Database Operations)JPA, java persistance api, java persistence layer interface, that is, some interfaces dealing with databases. The implementation is handed over to various vendors for implementation. ORM,

Mongodb Study Notes 03 -- query expressionMongodb Study Notes 03-query expression Not equal to, greater than, less! =: Db. stu. find ({name: {$ ne: 'billvsme '}) name is not 'billvsme'>: db. stu. find ({age: {$ gt: 18}) older than 18 :$ gte In/not

Research on oraclehashjointrace SQL> select * from v $ version;BANNER--------------------------------------------------------------------------------Oracle Database 11g Enterprise Edition Release 11.2.0.1.0-64bit ProductionPL/SQL Release

Use the API to convert unknown AR receipts into unverified status DECLARE p_api_version NUMBER; required VARCHAR2 (200); p_commit VARCHAR2 (200); Limit NUMBER; x_return_status VARCHAR2 (200); x_msg_count NUMBER; x_msg_data VARCHAR2 (200); Limit

Hibernate Association ingThis document serves as a learning note for the hibernate course for Ma soldiers at Beijing shangxue.com.Hibernate ing is mainly divided into one-to-one, one-to-many, one-to-one, and many-to-many. At the same time, it must

Common mongodb shell > Use cmd_test // create a database switched to db cmd_test> db. createCollection ("test") // create a table is the collection {"OK": 1}> db. db. addUser (db. group (db. adminCommand (db. groupcmd (db. auth (db. groupeval (db.

Mongodb distributed cluster (1. Master-slave replication)Understanding of distributed Clusters There are many explanations on the concept of distributed clusters. I prefer "distributed clusters" as two concepts, that is, distributed is one concept

Traverse all tables in the database and update the values of datetime columns. Declare @ tablename nvarchar (80) declare @ cloumn nvarchar (80) declare @ SQL nvarchar (400) declare c1 cursor scroll forselect table_name, column_name from information_

Analysis of Database Connection Pool (I) The database connection pool is used in recent projects ~, This topic is caused by a question when I write a mysql database. Generally, when the data is processed in the background, the server creates a