MongoDB

After installation, enter in the console: MONGO start the client. Show DBS displays all databases. Use XXX to select the database for the current database. Show collections displays all collections of the current database. Db.colleciton.find ()

Common JavaScript statements Copy Code code as follows: Db.getsiblingdb () Db.getcollectionnames () Db.getcollection () Db.printcollectionstats () Running JavaScript scripts on the MONGO shell To switch a database:

0x00 MongoDB Permissions Introduction 1.MongoDB installation does not add any parameters, the default is not permission to authenticate, the user can log on to the database any operation and remote access to the database, you need to start with the-

One of the biggest features of MongoDB is that it supports dynamic queries, just like traditional relational database queries, but its queries come in more flexible mode. One, query Expression Objects: Querying an Expression object The query

We know that MySQL in the installation of the need for us to set a database default username and password, MongoDB is no exception, but MongoDB is the default does not set access restrictions, do not need to enter a username and password can be

One, find operation Find is used in MongoDB to query, and all and part of the query can be implemented by specifying the first parameter of find. 1, all inquiries The empty query document {} will match the entire contents of the collection. If

Background Recently I was writing a test kit with a bug-recording system, because I was using Django and MongoDB in the background, and I ran into a problem with how to implement a self added field. The traditional relational database is very easy

Dump.js Copy Code code as follows: var c = db.user.find ({nick_name:{$exists: True, $ne: '}}). limit (100); while (C.hasnext ()) { Printjson (C.next ()); } MONGO 192.168.2.201:41211/dc_user dump.js > Feed.json The specified data

Increase Arbiter Add the profile mongod1,mongod2,mongod3 to the arbiter of Shard1,shard2,shard3 three set sets, respectively. Copy Code code as follows: Replset=shard1 Replset=shard2 Replset=shard3 Start the Mongod

MongoDB default set to No access restriction note: Research results based on Windows platform After successfully deploying MongoDB, enter the console: \ Input command: Mongod use admin, You will find that the DB contains a system.user table, hehe,

MongoDB log files in the case of setting logappend=true, will continue to the same log file appended, the time is long, naturally become very large. Resolved as follows: (Special note: The boot must be--logpath specified log path) Connecting to

Step1: Download Https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-2.4.11.tgz The latest version, this is the linux64 bit download address, you can also go to the homepage of their own choice Step2: Extract the Tar vxf mongodb-linux-x86_64-2.4.

In the next chapter, this article mainly said, MongoDB group function, do or quite powerful, quite for find (), skip (), distinct (), etc., the use of more complex. Test data: Copy Code code as follows: > Db.fruit.find (); {"_id": 1

We look at MongoDB from an administrator's point of view, as an administrator, we are often exposed to 4 main areas: 1. Install deployment 2. State Monitoring 3. Security certification 4. Backup and Recovery, Here we will explain the 1.1 points.

There is another cluster in the MongoDB, the partitioning technology, similar to the table partitioning of SQL Server, we know that when the amount of data reaches the T level, our disk, memory is too high, how to deal with such a scenario how we

These days the project revision, the time is comparatively tight, the blog also did not keep abreast, also hoped everybody forgive me. Well, today sharing the basic operation of the index in the MongoDB, we do not avoid the day-to-day development

1. Create a Super User Use admin db.createuser ( { User: "Adminusername", pwd: "UserPassword", roles: [ { roles: "Useradminanydatabase", DB: "admin" } ) There are two types of superuser

1, error procedure, direct Update table > db.system.users.update ({"_id": ObjectId ("529e67553992b24438d5e315")},{"user": "Tank2", "readOnly": false, "PWD" : "123"}) > Db.system.users.find (); {"_id": ObjectId ("529e5f8474b4c660718a70f3"),

The MongoDB database foreach statement circular traversal function is a very common function.A foreach loop is used to iterate, and the callback function is allowed to execute once per loop.In addition, the Foreach Loop traversal is an extension of

Insert () Method:The following is a document that inserts a three field into the inventory collection: Copy Code code as follows: Db.inventory.insert ({_id:10, type: "Misc", Item: "Card", qty:15}) In the real example, the document