一、理论
mongodb是一个文档型数据库，数据以类似json的文档形式存储。
mongodb用于应对大数据量、高性能和灵活性需求。
mongodb使用集合（collections）来组织文档（documents），每个文档都是由键值对组成的。
mongodb专业术语
sql术语 mongodb术语/概念 解释/说明
database database 数据库
table collection 数据库表/集合
row document 数据记录行/文档
column field 数据字段/域
index index 索引
table joins 表连接，mongodb不支持
primary key primray key 主键，mongodb自动将_id字段设置为主键
数据结构
database
collection
document
库中可包含一个或多个collection（集合），集合是一组document（文档）的容器，一个集合中的文档不需要有一个固定的模式。
二、实践
bash
[root@localhost ~]# dnf -y install libcurl openssl gcc make perl
[root@localhost ~]# tar zxf mongodb-linux-x86_64-rhel8-8.0.8.tgz
[root@localhost ~]# mv mongodb-linux-x86_64-rhel88-8.0.8 /usr/local/mongodb
[root@localhost ~]# echo 'export PATH=/usr/local/mongodb/bin:$PATH' >> /etc/profile
[root@localhost ~]# source /etc/profile
mongodb默认数据存储目录 /var/lib/mongodb 日志文件目录 /var/log/mongodb
在这里，提前创建这俩目录并设置当前用户有读写权限。
[root@localhost ~]# mkdir -p /var/lib/mongo
[root@localhost ~]# mkdir -p /var/log/mongodb
[root@localhost ~]# chown `whoami` /var/lib/mongo
[root@localhost ~]# chown `whoami` /var/log/mongodb
安装mongodb依赖的openssl11
[root@localhost ~]# tar zxf openssl-1.1.1w.tar.gz
[root@localhost ~]# cd openssl-1.1.1w
[root@localhost openssl-1.1.1w]# ./config --prefix=/opt/openssl11 --openssldir=/opt/openssl11/ssl
[root@localhost openssl-1.1.1w]# make -j$(nproc)
[root@localhost openssl-1.1.1w]# make install
[root@localhost ~]# echo 'export LD_LIBRARY_PATH=/opt/openssl11/lib:$LB_LIBRARY_PATH' | tee /etc/profile.d/openssl11.sh
export LD_LIBRARY_PATH=/opt/openssl11/lib:$LB_LIBRARY_PATH
[root@localhost ~]# source /etc/profile.d/openssl11.sh
启动mongodb
[root@localhost ~]# mongod --dbpath /var/lib/mongo --logpath /var/log/mongodb/mongod.log --fork
about to fork child process, waiting until server is ready for connections.
forked process: 12576
child process started successfully, parent exiting
安装mongodb shell
[root@localhost ~]# tar zxf mongosh-2.5.0-linux-x64-openssl3.tgz
[root@localhost ~]# cd mongosh-2.5.0-linux-x64-openssl3
[root@localhost mongosh-2.5.0-linux-x64-openssl3]# cd bin/
[root@localhost bin]# cp mongosh /usr/local/bin/
[root@localhost bin]# cp mongosh_crypt_v1.so /usr/local/lib/
启动mongodb shell
[root@localhost ~]# mongosh
Current Mongosh Log ID: 6805b5241958b5d28d1b26ff
Connecting to: mongodb://127.0.0.1:27017/?directConnection=true&serverSelectionTimeoutMS=2000&appName=mongosh+2.5.0
Using MongoDB: 8.0.8
Using Mongosh: 2.5.0
For mongosh info see: https://www.mongodb.com/docs/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.
------
The server generated these startup warnings when booting
2025-04-21T10:57:04.875+08:00: Using the XFS filesystem is strongly recommended with the WiredTiger storage engine. See http://dochub.mongodb.org/core/prodnotes-filesystem
2025-04-21T10:57:05.730+08:00: Access control is not enabled for the database. Read and write access to data and configuration is unrestricted
2025-04-21T10:57:05.730+08:00: You are running this process as the root user, which is not recommended
2025-04-21T10:57:05.730+08:00: This server is bound to localhost. Remote systems will be unable to connect to this server. Start the server with --bind_ip <address> to specify which IP addresses it should serve responses from, or with --bind_ip_all to bind to all interfaces. If this behavior is desired, start the server with --bind_ip 127.0.0.1 to disable this warning
2025-04-21T10:57:05.730+08:00: Soft rlimits for open file descriptors too low
2025-04-21T10:57:05.730+08:00: For customers running the current memory allocator, we suggest changing the contents of the following sysfsFile
2025-04-21T10:57:05.730+08:00: We suggest setting the contents of sysfsFile to 0.
2025-04-21T10:57:05.731+08:00: We suggest setting swappiness to 0 or 1, as swapping can cause performance problems.
------
test>
查看数据库列表
test> show dbs
admin 40.00 KiB
config 60.00 KiB
local 40.00 KiB
查看当前数据库
test> db
test
创建数据库
test> use runoob
switched to db runoob
runoob> db
runoob
runoob>
新创建的数据库不写数据，在数据库列表中看不到。
runoob> show dbs
admin 40.00 KiB
config 60.00 KiB
local 40.00 KiB
runoob> db.runoob.insertOne({"name":"zhangsan"})
{
acknowledged: true,
insertedId: ObjectId('6805b5d21958b5d28d1b2700')
}
runoob> show dbs
admin 40.00 KiB
config 60.00 KiB
local 40.00 KiB
runoob 40.00 KiB
删除当前使用的数据库及其所有集合
runoob> use myDatabase
switched to db myDatabase
myDatabase> db.dropDatabase()
查看当前库已有集合
runoob> show collections
runoob
runoob> show tables
runoob
创建一个集合的实例。
具有特性：
固定大小，最大10MB，最多存储5000个文档。
文档必须包含name和email字段，其中name必须是字符串，email必须是有效的电子邮件格式。
验证级别为严格，验证失败将阻止插入或更新。
使用WiredTiger存储引擎，指定块压缩器为zstd。
默认使用英语排序规则。
runoob> db.createCollection("myComplexCollection",{
capped:true,
size:10485760,
max:5000,
validator:{ $jsonSchema: {
bsonType: "object",
required: ["name","email"],
properties: {
name: {
bsonType: "string",
description: "string"
},
email: {
bsonType: "string",
pattern: "^.+@.+$",
description: "string"
}
}
}},
validationLevel: "strict",
validationAction: "error",
storageEngine: {
wiredTiger: { configString: "block_compressor=zstd"}
},
collation: { locale: "en",strength:2}
});
{ ok: 1 }
在test数据库中创建runoob集合。
test> db.createCollection("runoob")
{ ok: 1 }
注意：在mongodb中，集合只有在内容插入后才会创建，就是说，创建集合（数据表）后要再插入一个文档（记录），集合才会真正创建。
更新集合名
test> db.adminCommand({ renameCollection: "test.runoob",to: "test.aaa" });
{ ok: 1 }
删除集合
test> show collections
aaa
test> db.aaa.drop()
true
test> show collections
再次查看，发现已被删除。
在集合中插入单个文档
test> db.myCollection.insertOne({
... name: "Alice",
... age: 25,
... city: "New York"
... });
{
acknowledged: true,
insertedId: ObjectId('6805baf51958b5d28d1b2701')
}
在集合中插入多个文档
test> db.myCollection.insertMany([
... {name:"Bob",age:30,city:"Los Angeles"},
... {name:"Charlie",age:35,city:"Chicago"}]);
{
acknowledged: true,
insertedIds: {
'0': ObjectId('6805bb781958b5d28d1b2702'),
'1': ObjectId('6805bb781958b5d28d1b2703')
}
}
查找所有文档
test> db.myCollection.find();
[
{
_id: ObjectId('6805baf51958b5d28d1b2701'),
name: 'Alice',
age: 25,
city: 'New York'
},
{
_id: ObjectId('6805bb781958b5d28d1b2702'),
name: 'Bob',
age: 30,
city: 'Los Angeles'
},
{
_id: ObjectId('6805bb781958b5d28d1b2703'),
name: 'Charlie',
age: 35,
city: 'Chicago'
}
]
按条件查找文档
test> db.myCollection.find({age:{ $gt:25}}); $gt表示大于
[
{
_id: ObjectId('6805bb781958b5d28d1b2702'),
name: 'Bob',
age: 30,
city: 'Los Angeles'
},
{
_id: ObjectId('6805bb781958b5d28d1b2703'),
name: 'Charlie',
age: 35,
city: 'Chicago'
}
]
按条件查找文档，并只返回指定字段。
test> db.myCollection.find(
... { age: { $gt:25}},
... {name: 1,age:1,_id:0});
[ { name: 'Bob', age: 30 }, { name: 'Charlie', age: 35 } ]
注： { name: 1, age:1, _id:0 } -投影（Projection） 用于控制返回的字段（类似SQL中的select语句） ：1表示包含该字段， 0表示排除该字段。 例如 _id:0 表示排除默认返回的 _id字段。所以最终返回的文档仅包含name和age字段。
查找单个文档
test> db.myCollection.findOne({name:"Alice"});
{
_id: ObjectId('6805baf51958b5d28d1b2701'),
name: 'Alice',
age: 25,
city: 'New York'
}
查找单个文档，并只返回指定字段。
test> db.myCollection.findOne(
... {name:"Alice"},
... {name:1,age:1,_id:0});
{ name: 'Alice', age: 25 }
删除匹配过滤器的单个文档
test> db.myCollection.deleteOne({name:"Alice"});
{ acknowledged: true, deletedCount: 1 }
删除所有匹配过滤器的文档。
test> db.myCollection.deleteMany({name:"Bob"});
{ acknowledged: true, deletedCount: 1 }
返回被删除的文档，如果找不到匹配的文档，则返回null。
test> db.myCollection.findOneAndDelete(
... {name:"Charlie"},
... {projection:{name:1,age:1}}
... );
{ _id: ObjectId('6805bb781958b5d28d1b2703'), name: 'Charlie', age: 35 }
插入测试数据
test> db.myCollection.insertMany([{name:"Alice",age:25,city:"Los Angeles",status:"inactive"},{name:"Bob",age:30,city:"Los Angeles",status:"active"},{name:"Charlie",age:35,city:"Chicago",status:"active"}]);
{
acknowledged: true,
insertedIds: {
'0': ObjectId('6805bf3a1958b5d28d1b2704'),
'1': ObjectId('6805bf3a1958b5d28d1b2705'),
'2': ObjectId('6805bf3a1958b5d28d1b2706')
}
}
更新单个文档
test> db.myCollection.updateOne(
... {name:"Alice"},
... {$set:{age:26}});
{
acknowledged: true,
insertedId: null,
matchedCount: 1,
modifiedCount: 1,
upsertedCount: 0
}
更新多个文档
test> db.myCollection.updateMany(
... {age:{$lt:30}},
... {$set:{status:"active"}});
{
acknowledged: true,
insertedId: null,
matchedCount: 1,
modifiedCount: 1,
upsertedCount: 0
}
替换单个文档
test> db.myCollection.replaceOne(
... {name:"Bob"},
... {name:"Bob",age:31});
{
acknowledged: true,
insertedId: null,
matchedCount: 1,
modifiedCount: 1,
upsertedCount: 0
}
查找并更新单个文档
test> db.myCollection.findOneAndUpdate(
... {name:"Charlie"}, 过滤条件
... {$set:{age:36}}, 更新操作
... {returnDocument:"after"}); 可选参数，返回更新后的文档
{
_id: ObjectId('6805bf3a1958b5d28d1b2706'),
name: 'Charlie',
age: 36,
city: 'Chicago',
status: 'active'
}
安装备份与恢复命令
[root@localhost ~]# rpm -ivh mongodb-database-tools-rhel70-x86_64-100.12.0.rpm
[root@localhost ~]# mongodump # 执行此命令后，客户端会连接到ip为127.0.0.1 端口为27017的mongodb服务上，并备份所有数据到命令执行所在的目录下的dump/目录中。
2025-04-21T11:52:47.603+0800 writing admin.system.version to dump/admin/system.version.bson
2025-04-21T11:52:47.605+0800 done dumping admin.system.version (1 document)
2025-04-21T11:52:47.607+0800 writing test.myCollection to dump/test/myCollection.bson
2025-04-21T11:52:47.608+0800 writing runoob.myComplexCollection to dump/runoob/myComplexCollection.bson
2025-04-21T11:52:47.719+0800 done dumping test.myCollection (3 documents)
2025-04-21T11:52:47.720+0800 done dumping runoob.myComplexCollection (0 documents)
2025-04-21T11:52:47.722+0800 writing runoob.runoob to dump/runoob/runoob.bson
2025-04-21T11:52:47.723+0800 done dumping runoob.runoob (1 document)
[root@localhost ~]# ls
anaconda-ks.cfg
dump
[root@localhost ~]# cd dump
[root@localhost dump]# ls
admin prelude.json runoob test
执行此命令恢复数据，会从当前执行命令的路径下的dump目录中读取备份数据。
[root@localhost ~]# mongorestore
2025-04-21T11:54:56.322+0800 using default 'dump' directory
2025-04-21T11:54:56.322+0800 preparing collections to restore from
2025-04-21T11:54:56.322+0800 don't know what to do with file "dump/prelude.json", skipping...
2025-04-21T11:54:56.322+0800 reading metadata for runoob.myComplexCollection from dump/runoob/myComplexCollection.metadata.json
2025-04-21T11:54:56.323+0800 reading metadata for runoob.runoob from dump/runoob/runoob.metadata.json
2025-04-21T11:54:56.323+0800 reading metadata for test.myCollection from dump/test/myCollection.metadata.json
2025-04-21T11:54:56.325+0800 restoring to existing collection test.myCollection without dropping
2025-04-21T11:54:56.325+0800 restoring test.myCollection from dump/test/myCollection.bson
2025-04-21T11:54:56.327+0800 restoring to existing collection runoob.runoob without dropping
2025-04-21T11:54:56.327+0800 restoring runoob.runoob from dump/runoob/runoob.bson
2025-04-21T11:54:56.381+0800 restoring to existing collection runoob.myComplexCollection without dropping
2025-04-21T11:54:56.381+0800 restoring runoob.myComplexCollection from dump/runoob/myComplexCollection.bson
2025-04-21T11:54:56.388+0800 continuing through error: E11000 duplicate key error collection: runoob.runoob index: _id_ dup key: { _id: ObjectId('6805b5d21958b5d28d1b2700') }
2025-04-21T11:54:56.406+0800 continuing through error: E11000 duplicate key error collection: test.myCollection index: _id_ dup key: { _id: ObjectId('6805bf3a1958b5d28d1b2704') }
2025-04-21T11:54:56.406+0800 continuing through error: E11000 duplicate key error collection: test.myCollection index: _id_ dup key: { _id: ObjectId('6805bf3a1958b5d28d1b2705') }
2025-04-21T11:54:56.406+0800 continuing through error: E11000 duplicate key error collection: test.myCollection index: _id_ dup key: { _id: ObjectId('6805bf3a1958b5d28d1b2706') }
2025-04-21T11:54:56.406+0800 finished restoring test.myCollection (0 documents, 3 failures)
2025-04-21T11:54:56.406+0800 finished restoring runoob.myComplexCollection (0 documents, 0 failures)
2025-04-21T11:54:56.406+0800 finished restoring runoob.runoob (0 documents, 1 failure)
2025-04-21T11:54:56.406+0800 no indexes to restore for collection runoob.myComplexCollection
2025-04-21T11:54:56.406+0800 no indexes to restore for collection runoob.runoob
2025-04-21T11:54:56.406+0800 no indexes to restore for collection test.myCollection
2025-04-21T11:54:56.406+0800 0 document(s) restored successfully. 4 document(s) failed to restore.
创建用户并分配readWrite和dbAdmin角色
test> db.createUser({
... user:"testuser",
... pwd:"password123",
... roles:[
... {role:"readWrite",db:"<test>"},
... {role:"dbAdmin",db:"<test>"}
... ]})
{ ok: 1 }
验证用户
test> db.auth("testuser","password123")
{ ok: 1 }
vim /usr/local/mongodb/mongod.conf
mongod -f /usr/local/mongodb/mongod.conf
or
mongod --auth --dbpath /var/log/mongo --logpath /var/log/mongodb/mongod.log -fork
[root@bogon mongo]# mongod --auth --dbpath /var/lib/mongo --logpath /var/log/mongodb/mongodb.log --fork
about to fork child process, waiting until server is ready for connections.
forked process: 2484
child process started successfully, parent exiting
没有该文件，需要手动创建
[root@bogon mongo]# vim /usr/local/mongodb/mongod.conf
security:
authorization:"enabled"
[root@bogon mongo]# mongosh
test> use testdb
switched to db testdb
testdb> db.createUser({
... user: "testuser",
... pwd: "password123",
... roles:[{ role: "readWrite",db: "testdb" },{ role: "read", db: "testdb"
... }]})
{ ok: 1 }
[root@bogon mongo]# mongosh --host localhost --port 27017 -u "testuser" -p "password123" --authenticationDatabase "testdb"
Current Mongosh Log ID: 6847a2982a6fba6bcd1b26ff
Connecting to: mongodb://<credentials>@localhost:27017/?directConnection=true&serverSelectionTimeoutMS=2000&authSource=testdb&appName=mongosh+2.5.0
Using MongoDB: 8.0.8
Using Mongosh: 2.5.0
mongosh 2.5.2 is available for download: https://www.mongodb.com/try/download/shell
For mongosh info see: https://www.mongodb.com/docs/mongodb-shell/
test> use testdb;
switched to db testdb
testdb> show collections;
testdb> exit
以上方式验证成功
还可以将配置文件写全一些
[root@bogon mongo]# vim /usr/local/mongodb/mongod.conf
# 系统日志配置
systemLog:
destination: file
path: /var/log/mongodb/mongod.log
logAppend: true
timeStampFormat: iso8601-utc
# 存储配置
storage:
dbPath: /var/lib/mongo
# journal选项在8.0+版本已移除，journaling总是启用
# 进程管理
processManagement:
fork: true
pidFilePath: /tmp/mongod.pid
# 网络配置
net:
bindIp: 127.0.0.1
port: 27017
# 安全配置
security:
authorization: enabled
然后用mongod -f /usr/local/mongodb/mongod.conf 指定配置文件来启动。
[root@bogon mongo]# pkill mongo
[root@bogon mongo]# mongod -f /usr/local/mongodb/mongod.conf
about to fork child process, waiting until server is ready for connections.
forked process: 2604
child process started successfully, parent exiting
[root@bogon mongo]# mongosh --host localhost --port 27017 -u "testuser" -p "password123" --authenticationDatabase "testdb"
Current Mongosh Log ID: 6847ab314825ef18a31b26ff
Connecting to: mongodb://<credentials>@localhost:27017/?directConnection=true&serverSelectionTimeoutMS=2000&authSource=testdb&appName=mongosh+2.5.0
Using MongoDB: 8.0.8
Using Mongosh: 2.5.0
mongosh 2.5.2 is available for download: https://www.mongodb.com/try/download/shell
For mongosh info see: https://www.mongodb.com/docs/mongodb-shell/
test> use testdb
switched to db testdb
testdb> show collections;
testdb>