Mongdb安装，Shell命令以及java集成

安装mongodb

https://blog.youkuaiyun.com/weixin_39739846/article/details/110856011

mongo -version 查看mongo版本

sudo service mongod start #启动mongo
sudo service mongod stop #关闭mongo
sudo service mongod restart #重启mongo

Shell

show dbs						#显示数据库列表
show collections		#显示当前数据库中的集合（类似关系数据库中的表table）
show users					#显示所有用户
use yourDB					#切换当前数据库至yourDB，如果数据库不存在，则创建数据库

#MongoDB没有单独创建集合名的shell命令，在插入数据的时候，MongoDB会自动创建对应的集合。
db.COLLECTION_NAME.insert(document) 
#e.g.
 db.student.insert(
	{
		'name': 'lisi',
		'score': {
			'English': 55,
			'Math': 100,
			'Computer': 88
		}
	}
);
#查询方法
db.COLLECTION_NAME.find(条件,返回结果)
#e.g.
db.student.find({name:"zhangsan"},{"_id":0,"score":1});#0表示不返回，1表示返回


# 查询worker集合中name属性是"majinqiao"的数据
# pretty函数 ，以格式化的方式显示查询结果
db.worker.find({name:"majinqiao"}).pretty()

# or查询 name = "majinqiao" or score = 54
db.worker.find({$or:[{name:"majinqiao"},{score:54}]}).pretty()

# or查询  age < 30 or age > 50
db.worker.find({$or:[{age:{$lt:30}},{age:{$gt:50}}]})

# or查询  age <= 30 or age => 50
db.worker.find({$or:[{age:{$lte:30}},{age:{$gte:50}}]})

# and查询  age != 30 and name != 'chengya'
db.worker.find({age:{$ne:30},age:{$ne:50}})

# and查询，name = "majinqiao" and age = 36
db.worker.find({name:"majinqiao",age:36}).pretty()

# 查找name字段为字符串的数据
db.worker.find({name:{$type:"string"}})

# 限制查询结果条数为2条
db.worker.find({name:"zhangjian"}).limit(2)

# province字段正序排列，city_age字段倒序排列
db.city.find().sort({province:1,city_age:-1})

# 当limit，skip，sort同时出现时，逻辑顺序为sort，skip，limit
db.worker.find({name:"zhangjian"}).limit(2).skip(1).sort({score:1})

# 查询city集合中存在history字段，且history的值是null的数据
db.city.find({history:{$in:[null],$exists:true}})

# select _id,city_name as cityName from city where city_name = 'jingzhou' and city_age >= 10
# _id 是默认查询的，如果想不返回这个字段， _id:0 即可
db.city.find({city_name:"jingzhou",city_age:{$gte:10}},{cityName:"$city_name"})

Java

导入依赖项

导入依赖或引入jar包

<dependency>
  <groupId>org.mongodb</groupId>
  <artifactId>mongo-java-driver</artifactId>
  <version>3.12.11</version>
</dependency>

mongo-java-driver-3.2.2.zip

连接数据库和集合

MongoClient mongoClient = new MongoClient("localhost", 27017);
MongoDatabase database = mongoClient.getDatabase("test");	//数据库
MongoCollection<Document> student = database.getCollection("student");	//集合

插入数据

 public static void main(String[] args) {
        MongoClient mongoClient = new MongoClient("localhost", 27017);
        MongoDatabase database = mongoClient.getDatabase("test");
        MongoCollection<Document> student = database.getCollection("student");
        Document score = new Document("English",45).append("Math",89).append("Computer",100);
        Document doc = new Document("name","scofield").append("score",score);
        student.insertOne(doc);
    }

查询数据

public static void main(String[] args) {
        MongoClient mongoClient = new MongoClient("localhost", 27017);
        MongoDatabase database = mongoClient.getDatabase("test");
        MongoCollection<Document> student = database.getCollection("student");
        FindIterable<Document> iterable = student.find(new BasicDBObject("name","scofield"));
        for(Document doc : iterable){
            System.out.println(doc.get("score"));
        }
}

https://blog.youkuaiyun.com/yangning5850/article/details/18738651

旧版API

连接数据库

import com.mongodb.MongoClient;
……//这里省略其他需要导入的包

public class MongoDBJDBC{
    public static void main( String args[] ){
        try{   
            // 连接到 mongodb 服务
            MongoClient mongoClient = new MongoClient( "localhost" , 27017 );
            // 连接到数据库
            DB db = mongoClient.getDB( "test" );
            System.out.println("Connect to database successfully");
            boolean auth = db.authenticate(myUserName, myPassword);
            System.out.println("Authentication: "+auth);
        }catch(Exception e){
            System.err.println( e.getClass().getName() + ": " + e.getMessage() );
        }
    }
}

创建集合

可以使用com.mongodb.DB类中的createCollection()来创建集合

public class MongoDBJDBC{
   public static void main( String args[] ){
      try{   
	     // 连接到 mongodb 服务
         MongoClient mongoClient = new MongoClient( "localhost" , 27017 );
         // 连接到数据库
         DB db = mongoClient.getDB( "test" );
	 System.out.println("Connect to database successfully");
         boolean auth = db.authenticate(myUserName, myPassword);
	 System.out.println("Authentication: "+auth);
         DBCollection coll = db.createCollection("mycol");
         System.out.println("Collection created successfully");
      }catch(Exception e){
	     System.err.println( e.getClass().getName() + ": " + e.getMessage() );
	  }
   }
}

插入文档

可以使用com.mongodb.DBCollection类的 insert() 方法来插入一个文档

public class MongoDBJDBC{
   public static void main( String args[] ){
      try{   
	 // 连接到 mongodb 服务
         MongoClient mongoClient = new MongoClient( "localhost" , 27017 );
         // 连接到数据库
         DB db = mongoClient.getDB( "test" );
	 System.out.println("Connect to database successfully");
         boolean auth = db.authenticate(myUserName, myPassword);
	 System.out.println("Authentication: "+auth);         
         DBCollection coll = db.getCollection("mycol");
         System.out.println("Collection mycol selected successfully");
         BasicDBObject doc = new BasicDBObject("title", "MongoDB").
            append("description", "database").
            append("likes", 100).
            append("url", "http://www.w3cschool.cc/mongodb/").
            append("by", "w3cschool.cc");
         coll.insert(doc);
         System.out.println("Document inserted successfully");
      }catch(Exception e){
	     System.err.println( e.getClass().getName() + ": " + e.getMessage() );
	  }
   }
}