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【原创】大数据基础之Mongodb(2)常用查询命令

时间:2021-07-01 10:21:17 帮助过:1人阅读

1 下载

https://www.mongodb.com/download-center/community

比如:

https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-4.0.9.tgz

2 连接

# cd $MONGODB_HOME
# bin/mongo master:27017/database_name

3 查询

1 count

>db.getCollection(‘table_name‘).find({}).count()

2 group by

>db.getCollection(‘table_name‘).aggregate([{"$group": {_id: "$column_name", count: {"$sum": 1}}}])

3 select by limit

>db.getCollection(‘table_name‘).find({}).limit(1).pretty()

4 select by condition ‘=’

>db.getCollection(‘table_name‘).find({"column_name": "column_value"})

5 select by condition ‘>’

>db.getCollection(‘table_name‘).find({"column_name":{$gt:"column_value"}}).pretty()

6 select by condition ‘or’

>db.getCollection(‘table_name‘).find({$or: [ {"column_name1":"column_value1"},{"column_name2":{$gt:"column_value2"}}]}).pretty()

 

【原创】大数据基础之Mongodb(2)常用查询命令

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