MongoDB的使用

进入MongoDB

因为版本是6.0，所以需要在终端输入mongosh，该命令相当于6.0版本之前的mongo命令

root@Mongodb:~# mongosh
Current Mongosh Log ID: 63f48e2e5d50ed0f2ed35d3c
Connecting to: mongodb://127.0.0.1:27017/?directConnection=true&serverSelectionTimeoutMS=2000&appName=mongosh+1.7.1
Using MongoDB: 6.0.4
Using Mongosh: 1.7.1

For mongosh info see: https://docs.mongodb.com/mongodb-shell/

To help improve our products, anonymous usage data is collected and sent to MongoDB periodically (https://www.mongodb.com/legal/privacy-policy).
You can opt-out by running the disableTelemetry() command.

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The server generated these startup warnings when booting
2023-02-21T16:54:50.226+08:00: Using the XFS filesystem is strongly recommended with the WiredTiger storage engine. See http://dochub.mongodb.org/core/prodnotes-filesystem
2023-02-21T16:54:50.700+08:00: Access control is not enabled for the database. Read and write access to data and configuration is unrestricted
2023-02-21T16:54:50.700+08:00: vm.max_map_count is too low
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Enable MongoDB's free cloud-based monitoring service, which will then receive and display
metrics about your deployment (disk utilization, CPU, operation statistics, etc).

The monitoring data will be available on a MongoDB website with a unique URL accessible to you
and anyone you share the URL with. MongoDB may use this information to make product
improvements and to suggest MongoDB products and deployment options to you.

To enable free monitoring, run the following command: db.enableFreeMonitoring()
To permanently disable this reminder, run the following command: db.disableFreeMonitoring()
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test>

4.2 查看MongoDB数据库中的所有数据库

test> show dbs
admin 40.00 KiB
config 12.00 KiB
local 40.00 KiB

4.3 打开或者新建一个数据库

MongoDB不需要预先创建文档，在使用时自动创建

test> use fib
switched to db fib
fib>

4.4 添加集合

集合相当于mysql数据库中的表

fib> db.createCollection('teacher')
{ ok: 1 }
fib> show collections
teacher

4.5 插入数据

fib> db.teacher.insert({_id:1,sname:'张三',sage:20})
DeprecationWarning: Collection.insert() is deprecated. Use insertOne, insertMany, or bulkWrite.
{ acknowledged: true, insertedIds: { '0': 1 } }

4.6 查询所有记录

fib> db.teacher.find()
[ { _id: 1, sname: '张三', sage: 20 } ]

4.7 更新操作

fib> db.teacher.update({_id:1},{$set:{sname:'李四'}})
DeprecationWarning: Collection.update() is deprecated. Use updateOne, updateMany, or bulkWrite.
{
acknowledged: true,
insertedId: null,
matchedCount: 1,
modifiedCount: 1,
upsertedCount: 0
}

4.8 查询

4.8.1 查询sname='李四'的记录

fib> db.teacher.find({sname:'李四'})
[ { _id: 1, sname: '李四', sage: 20 } ]

4.8.2 查询指定列sname数据

fib> db.teacher.find({},{sname:1})
[ { _id: 1, sname: '李四' } ]

4.8.3 AND条件查询

fib> db.teacher.find({sname:'李四',sage:20})
[ { _id: 1, sname: '李四', sage: 20 } ]

4.8.4 OR条件查询

fib> db.teacher.find({$or:[{sage:20},{sage:21}]})
[ { _id: 1, sname: '李四', sage: 20 } ]

4.8.5 格式化输出

fib> db.teacher.find().pretty()
[ { _id: 1, sname: '李四', sage: 20 } ]

4.9 删除

4.9.1 删除数据

fib> db.teacher.remove({sname:'李四'})
DeprecationWarning: Collection.remove() is deprecated. Use deleteOne, deleteMany, findOneAndDelete, or bulkWrite.
{ acknowledged: true, deletedCount: 1 }