mongodb sum with condition

Original link http://www.cnblogs.com/zhangzili/p/4975080.htmlMongoDB knowledge points at a glance1. Start the MongoDB database:Go to the MongoDB installation directory and execute the following commandC:\Program

This article mainly introduces the PHP operation MongoDB implementation of adding and removing functions, combined with examples of the form of a summary of the PHP operation MongoDB Common skills, and with PHP7 operation MongoDB method, with a

This article mainly introduces the PHP operation MongoDB implementation of adding and removing functions, combined with examples of the form of a summary of the PHP operation MongoDB Common skills, and with PHP7 operation MongoDB method, with a

1. Download extract MongoDB, configure environment variablesTAR-ZXVF mongodb-linux-x86_64-rhel62-3.2.7.tgzExport Path=/bin: $PATH2. Create a data Save directoryMkdir-p/data/db3.mongodb Boot./mongod//Default boot./mongod--dbpath=/data/db//Start

SumSum by conditionDb.aa.aggregate ([ {$group: {_id:null, total: {$sum: ' $value '}}},//$value refers to sum by that column. For example, value is a column of MONGO. So this should be $value

/*** MongoDB $type operator*/ /*** The $type operator is based on the Bson type to retrieve the matching data type in the collection and returns the result.* The types of MongoDB that can be used are shown in the following table:* Type Number Notes*

Some basics forget to check at any time.#整备恢复Mongodump--port 20001--authenticationdatabase=admin-u *-D lvlv-c lvlv-o/homeMongorestore--drop--host 172.16.201.74--port 20001--authenticationdatabase=admin-umgbackup-d test/tmp/liding/test

I. Download On the official MongoDB website, we found that there are 32bit and 64bit, which depends on your system, but here are two points of attention: ①: According to industry rules, the even number is "stable version" (for example, 1.6.X, 1.8.X),

Install and use mongodb 1. Install and start MongoDB Widndows and linux are basically the same 1. Download the database, Mongodb-linux-x86_64-ubuntu1404-3.0.3.tgz: linux 2. decompress the file and place it in a proper location. Tar-vxf mongodb-linux-

Start the corresponding SERVER:CD: Mongod--dbpath db Path to the Mangodb installation root directoryTo create the MANGODB service:Mongod.exe--logpath d:/mongodb/logs/mongodb.log--logappend--dbpath d:/mongodb/db--directoryperdb--serviceName