MongoDB

> Use mongo_test//CREATE DatabaseSwitched to DB Mongo_test> db.createcollection ("Test")//CREATE TABLE is the collection{"OK": 1}> DB.Db.adduser (Db.group (Db.admincommand (Db.groupcmd (Db.auth (Db.groupeval (Db.changeuserpassword (Db.hasownproperty

Query.all ("name", "a", "B");//match array with multiple elementsQuery.and (Query.eq ("name", "a"), Query.eq ("title", "T"));//satisfy multiple conditions at the same timequery.eq ("name", "a");//equalsquery.exists ("type", true);//Determine if key

OverviewShard Sharding is the separation of different data on different servers.Modelamong them:The user's operation to MongoDB is requested by the mongs.CONFIGSVR is used for saving, which data is stored on which shardHow to use ShardsStart 2 nodes

Download: [[email protected] mongodb_file]# wget http://fastdl.mongodb.org/linux/mongodb-linux-i686-1.8.2.tgz extract: [Email Protected] mongodb_file]# tar zxvf mongodb-linux-i686-1.8.2.tgzBuild folder:[Email protected] mongodb_file]#

MongoDB has established TTL (time to live) for the index since the 2.2 version, you can specify a field of type date as the index of the document and specify the TTL (in seconds), and the MongoDB internal checks the TTL every minute, and if it times

1. Installing the MongoDB DatabaseMongoDB Official website: https://www.mongodb.orgAfter installation, the following steps are played:The first step: Planning your installation directory and database file storage path, I intend to place MONGO

Back to CatalogMongoDB pipeline is a good thing, it can be many operations batch implementation, will be a number of commands into a pipeline, and then go to execute them sequentially, today I would like to say, the use of the pipeline in the

1. Documents, collections, and databasesA), documentation: Because MongoDB is a document-oriented database, it is conceivable that the document is its basic unit, equivalent to the row in the relational database!Ⅰ, which is an ordered set consisting

Install MongoDB on UbuntuKylin15.05Install MongoDB on Ubuntu Kylin15.05 MongoDB is a typical NoSQL, but it is also said that many people are using it. So I tried to install the database on Ubuntu Kylin. First, go to its official website. Link

Mongodb Study Notes 09 -- shard shardingOverview Shard sharding divides different data into different servers. Model Where: Partition + vH87XEPGJyIC8 + DQpjb25maWdzdnIg08PT2rGjtOajrMSzzPXK/partition = "how to use a partition"> how to use a

The database updates multiple records with different values and updates multiple fields at the same time Requirement The following two tables are student (student table) and score (test student table) Statistics: total score and average score of

Datazen Map Chart IntroductionZookeeper This article mainly introduces Datazen's support for map charts. Here you can see the types of map charts currently supported by Datazen and their own map data. Map charts under Datazen are of the same

Kettle date parameter usage When you use the date type parameter to compare the data size, make sure that the passed date type parameter and the comparison type are consistent. It is common to use date-type parameters in ETL. For example, the SQL

Redis _ redis PipelineRedis is a TCP server using the client-server model and what is called a Request/Response protocol.Redis uses a tcp-based client-server model, which can also be calledRequest/ResponseProtocol model. This means that usually a

Three statuses of Hibernate objects We all know that there are three statuses of Data Objects in hibernate, So what are these three statuses? How are they converted? What are these statuses used? With this series of problems, let's take a look at

And, or multi-condition query in explain Java // And, or multi-condition joint query // age condition (and condition) BasicDBList condList = new BasicDBList (); BasicDBObject cond = new BasicDBObject (); cond. put ("$ gt", 0); cond. put ("$ lte", 40

Mydumper installation and installation fault Summary Mydumper is a lightweight third-party open-source tool for mysql database backup. The backup method uses the term logical backup. It supports multithreading, And the backup speed is much higher

Mongodb Study Notes 02-CURD operationsMongodb Study Notes 02-CURD operations CURD indicates Create, Update, Read, and Delete operations. Create a database Directly use the database name and create a collection to create a database. Create collecion

About OGG & quot; LoadingdatafromfiletoReplicat & quot; key parameters for synchronizing partial records containing the lob field table Key parameters for synchronizing partial records containing the lob field table in OGG "Loading data from file to

MongoDB query commands 1. query all records Copy the Code as follows: db.userInfo.find(); Equivalent:Select * from userInfo;By default, 20 records are displayed on each page. If no record is displayed, you can use the it iteration command to query