mongoDB.md

MongoDB简介

1. 属于NoSQL之一，分布式文档数据库
2. 存储结构灵活，适应多变的表单数据
3. 提供灵活的查询方法

MongoDB基本操作命令

1. 库

   use xxx; //创建一个库进入或直接进入库

   db.dropDatabase() //删除当前库

   show databases //查看有哪些库

2. 集合

   • 添加

     db.xxx.insert(json值)

   • 查询

     db.xxx.find() //查询所有

     db.xxx.find(json值) //按条件查询

     db.xxx.find({"dno":{$gt:50}}) //查询dno>50的

     其他:$gt、$gte、$lt、$lte、$ne

     db.xxx.find({"dname":/java6/}) //查询dname 包含java6的记录

   • 更新

     db.xxx.update(条件,更新值)//全部更新

     db.xxx.update(条件,{$set:更新值}) //局部更新

   • 删除

     db.xxx.remove({}) //删除所有记录

     db.xxx.remove(json值) //删除指定条件记录

   • 统计数量

     db.dept.count({"dname":/java6/})

   • 删除集合

     db.dept.drop()

   • 查看有哪些集合

     show collections

Java访问MongoDB

1. 利用mongo-java-driver.jar

   测试获取库名

    @Test
    public void test1() throws Exception{
    	MongoClient mongo = new MongoClient("localhost",27017);
    	List<String> dbs = mongo.getDatabaseNames();//show databases
    	for(String s:dbs){
    		System.out.println("库名:"+s);
    	}
    	mongo.close();
    }
   

   创建dept集合插入记录

    @Test
    public void test2() throws Exception{
    	MongoClient mongo = new MongoClient("localhost",27017);
    	DB java16 = mongo.getDB("java16");//use java16
    	DBCollection dept = java16.getCollection("dept"); //获取dept集合
    	DBObject arr = new BasicDBObject();
    	arr.put("deptno", 30);
    	arr.put("dname", "H5");
    	arr.put("loc", "上海");
    	dept.insert(arr);
    	mongo.close();
    }
   

   查询dept集合记录

    @Test
    public void test3() throws Exception{
    	MongoClient mongo = new MongoClient("localhost",27017);
    	DB java16 = mongo.getDB("java16");//use java16
    	DBCollection dept = java16.getCollection("dept");
    	DBCursor cursor = dept.find();//db.dept.find()
    	while(cursor.hasNext()){
    		DBObject obj = cursor.next();
    		System.out.println(obj.get("deptno")+" "+obj.get("dname")+" "+obj.get("loc"));
    	}
    	mongo.close();
    }
   

   条件查询

    @Test
    public void test4() throws Exception{
    	MongoClient mongo = new MongoClient("localhost",27017);
    	DB java16 = mongo.getDB("java16");//use java16
    	DBCollection dept = java16.getCollection("dept");
    	DBObject params = new BasicDBObject();//{"loc":"北京"}
    	params.put("loc", "北京");
    	DBCursor cursor = dept.find(params);//db.dept.find({"loc":"北京"})
    	while(cursor.hasNext()){
    		DBObject obj = cursor.next();
    		System.out.println(obj.get("deptno")+" "+obj.get("dname")+" "+obj.get("loc"));
    	}
    	mongo.close();
    }
   

   更新记录

    @Test
    public void test5() throws Exception{
    	MongoClient mongo = new MongoClient("localhost",27017);
    	DB java16 = mongo.getDB("java16");//use java16
    	DBCollection dept = java16.getCollection("dept");
    	
    	DBObject q = new BasicDBObject();//{"deptno":10}
    	q.put("deptno", 10);
    	
    	DBObject o = new BasicDBObject();//{$set:{"dname":"JAVA"}}
    	DBObject attr1 = new BasicDBObject();
    	attr1.put("dname", "JAVA");
    	o.put("$set", attr1);
    	
    	dept.update(q, o);//db.dept.update({"deptno":10},{$set:{"dname":"JAVA"}})
    	
    	mongo.close();
    }
   

2. 使用spring-data-mongodb.jar工具

   MongoTemplate

   • 在pom.xml添加定义

     	<dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-data-mongodb</artifactId>
       </dependency>
     

   • 在application.properties定义mongo参数

       spring.data.mongodb.uri=mongodb://localhost:27017/ovls
     

   • 注入MongoTemplate操作

       @Autowired//注入
       private MongoTemplate mongo;
       
       @Autowired
       private SubjectMapper subjectDao;
       
       @Test//添加操作
       public void test1(){
       	Subject subject = subjectDao.selectByPrimaryKey(20);
       	//将subject写入到mongodb
       	//mongo.insert(subject,"t_subject");
       	mongo.insert(subject); //默认类型名做集合名
       }
       
       
       @Test//查询操作
       public void test2(){
       	List<Subject> list = mongo.findAll(Subject.class);
       	for(Subject s:list){
       		System.out.println(s.getId()+" "+s.getName()+" "+s.getDirectionId());
       	}
       }
       
       @Test//条件查询
       public void test3(){
       	Query query = new Query();
       	query.addCriteria(Criteria.where("directionId").is(1));//where directionId=1
       	List<Subject> list = mongo.find(query, Subject.class);
       	for(Subject s:list){
       		System.out.println(s.getId()+" "+s.getName()+" "+s.getDirectionId());
       	}
       }
       
       @Test//删除操作
       public void test4(){
       	Query query = new Query();
       	query.addCriteria(Criteria.where("id").is(1));
       	mongo.remove(query, Subject.class);//按指定条件删除
       	
       	Subject subject = new Subject();
       	subject.setId(20);
       	mongo.remove(subject);//删除指定对象，按id做条件删除
       }
       
       @Test//更新操作
       public void test5(){
       	Query query = new Query();
       	query.addCriteria(Criteria.where("id").is(2));
       	
       	Update update = new Update();
       	update.set("name", "JAVA");
       	
       	mongo.updateFirst(query, update, Subject.class);
       }