MongoDB

Greater than: $ GT Greater than or equal to: $ GTE Less than: $ lt Less than or equal to: $ LTE Not equal to: $ ne In: $ in Example 1: query the persons whose age is greater than 20 and   DB. XXX. Find ({"Age": {"$ gt": 20, "LTE": 30 }});

MongoDB documentation is similar to JSON format JSON data type: JSON contains six data types, including null, Boolean, number, String, array, and object. there is no date type in JSON, and there is only one numeric type. There is no way to

Reprinted from http://www.cnblogs.com/spnt/ The sharding maintenance of MongoDB is also about the several commands, which are relatively simple. We will use the example for demonstration. 1. List all shard servers Note that you need to

Assume that there is such a document:DB. XXX. Remove (); DB. xxx. insert ({"ID": 1, "members": [{"name": "buleriver1", "Age": 27, "gender": "M "}, {"name": "buleriver2", "Age": 23, "gender": "F" },{ "name": "buleriver3", "Age": 21, "gender": "M"}]});

Query records Common Query > Var cursor = dB. Things. Find (); > While (cursor. hasnext () printjson (cursor. Next ());The above example shows the cursor-style iterative output. The hasnext () function tells us whether there is any data. If so, you

Brief Introduction Capped collections is a set of excellent performance with a fixed size (Set of capacity), with LRU (least recently used) Rules and Insertion Sequence for age-out (aging removal) processing: automatically maintains the insertion

Recently, the San Francisco-based Stripe Company released mosql, which allows you to easily generate reports from MongoDB using a replicated PostgreSQL database. Mosql is based on mongoriver, which is also a product of stripe. It can monitor MongoDB

Primary learning of MongoDB master-slave Synchronization MongoDB master-slave Synchronization MongoDB master-slave synchronization is very simple. Host startup declares that you are the host. when starting the slave, you only need to declare that

Document directory 1. Preparation Information Processing (each node can be the same or different) 2. Start the mongod instance 3. Configure and initialize the replica set 4. view the replica set status 1. read/write splitting 2. automatic

Create document Insert data into MongoDB using insert, Example: DB. refactor. insert ({"refactor's blog": "http://www.cnblogs.com/refactor "}) This operation adds a "_ id" Key to the document and stores it in the database. Batch insert If you want

I have been very interested in the principles and practices of distributed systems for a long time, and I have been very curious about MongoDB. I have finally had time to experiment with it! I set up a replica sets + sharding test cluster

1. Download suitable mongodb Official Website: http://www.mongodb.org/downloads MongoDB for Windows has three versions: MongoDB for Windows Server 2008 R2 only runs on Windows Server 2008 R2, Windows 7 64-bit, and updated Windows versions. This

MongoDB is a database server: it runs on the frontend or backend and waits for the user's connection. When you start MongoDB, the following results are displayed: ~/$ ./mongod ## some logging output # Tue Mar 9 11:15:43 waiting for connections on

Here we will not describe what MongoDB is. It mainly solves the problem of storing large data volumes. You can search for the keyword "MongoDB.   Windows version: 1, download: http://www.mongodb.org/downloads 2, download the latest stable

Mongodb DBObject supports saving multi-dimensional arrays. When adding elements, use the "$ push" operator and "$ pull" When deleting elements ". However, the problem arises when updating. mongodb first supports "$" to locate an element in the array,

Object IDs Documents in mongodb must be identified by a unique keyword _ id. _ Id field Almost every mongodb document uses the _ id field as the first attribute (with some exceptions in the system set and Capacity Set (capped collection ). The _ id

Create an index in the background By default, index creation will block other database operations. V1.3.2 and later provide the background index creation function. Delete Index Delete all indexes of a specified

Mongodb provides an interesting "Multi-key" feature that automatically indexes the array values of objects. Tags are a good example. Suppose you have an article that contains many classification tags: $ dbshell> db.articles.save( { name: "Warm

MongoDB supports two-dimensional geographic information indexing. It is designed for location-based queries in the mind, such as "finding N places closest to my location ". It can also efficiently process additional query conditions, such as

Single Point   AVG MAX Min Insert 12463 23960 1170 Updade 7197 8955 4752 Select 17675 19233 8566 Delete 7289 8800 1040 Insert: update: select: delete =