Java操作mongodb增删改查的基本操作实战指南

show dbs；

use 库名；

db；

db.dropDatabase();

public class AddDemo {
	public static void main(String[] args) {
		//获取链接
		MongoClient mc = new MongoClient("localhost",27017);
		//获取库对象
		MongoDatabase db = mc.getDatabase("student");
		//获取集合对象
		MongoCollection<Document> collection = db.getCollection("student");
		//新增
		Document document = new Document();
		document.put("name", "周子舒");
		document.put("sex", "男");
		document.put("age", 18);
		document.put("birthday",new Date());
		
		//添加一条数据
		collection.insertOne(document);
		
		//添加多条数据
		Document document1= new Document();
		document1.put("name", "钟无艳");
		document1.put("sex", "女");
		document1.put("age", 18);
		document1.put("birthday",new Date());
		
		Document document2= new Document();
		document2.put("name", "貂蝉");
		document2.put("sex", "女");
		document2.put("age", 1);
		document2.put("birthday",new Date());
		
		ArrayList<Document> list = new ArrayList<Document>();
		list.add(document1);
		list.add(document2);
		collection.insertMany(list);
		mc.close();
	}
}

public void deleteOneTest(){
    public static void main(String[] args) {
        //获取链接
		MongoClient mc = new MongoClient("localhost",27017);
		//获取库对象
		MongoDatabase db = mc.getDatabase("student");
		//获取集合对象
		MongoCollection<Document> collection = db.getCollection("student");
        //删除条件
        Bson filter = Filters.eq("age",18);
        //删除与筛选器匹配的单个文档
        collection.deleteOne(filter);
        mc.close();
    }
}

 Filters.eq()   //匹配到等于指定值的数据
 Filters.gt()   //匹配到大于指定值的数据
 Filters.gte()   //匹配到大于等于定值的数据
 Filters.lt()   //匹配到小于指定值的数据

public class DeleteDemo {
	public static void main(String[] args) {
		//获取链接
		MongoClient mc = new MongoClient("localhost",27017);
		//获取库对象
		MongoDatabase db = mc.getDatabase("student");
		//获取集合对象
		MongoCollection<Document> collection = db.getCollection("student");
//		Bson exists=Filters.exists("age",false);
		Bson gt=Filters.gt("age", 100);
//		Bson age=Filters.exists("age");
		DeleteResult deleteMany = collection.deleteMany(gt);
		System.out.println(deleteMany);
		mc.close();
	}
}

public class UpdateDemo {
	public static void main(String[] args) {
		//获取链接
				MongoClient mc = new MongoClient("localhost",27017);
				//获取库对象
				MongoDatabase db = mc.getDatabase("student");
				//获取集合对象
				MongoCollection<Document> collection = db.getCollection("student");
	//			Bson eq = Filters.eq("name","吕布");
				//修改一条数据
//				UpdateResult updateOne = collection.updateOne(eq, new Document("$set",new Document("age",99)),new UpdateOptions().upsert(true));
//				System.out.println(updateOne);
				//修改多条数据
				Bson and=Filters.and(Filters.gt("age",20),Filters.lte("age", 100));
//				UpdateResult updateMany = collection.updateMany(eq, new Document("$set",new Document("age",3)));
				UpdateResult updateMany = collection.updateMany(and, new Document("$inc",new Document("age",100)));
				System.out.println(updateMany);
				mc.close();
	}
}

Bson b=Filters.regex("name","张");//查出所有姓张的数据

FindIterable<Document> b=collection.find().skip(0).limit(3);//跳过第0条数据，一次看三条数据

Bson b=new Document("id",-1);//根据id倒叙排序
FindIterable<Document> d=collection.find().sort(b);

public class SelectDemo {
	public static void main(String[] args) {
		//获取链接
		MongoClient mc = new MongoClient("localhost",27017);
		//获取库对象
		MongoDatabase db = mc.getDatabase("student");
		//获取集合对象
		MongoCollection<Document> collection = db.getCollection("student");
		// 添加条件
				Bson eq = Filters.regex("name", "张");
				Document document = new Document("birthday",-1);
				// .limit(2).skip(2)
				FindIterable<Document> find = collection.find(eq).sort(document);
				List<Student>  slist = new ArrayList<Student>();
				MongoCursor<Document> iterator = find.iterator();
				while(iterator.hasNext()) {
					Student s =  new Student();
					Document next = iterator.next();
					s.setSname(next.getString("name"));
					s.setSsex(next.getString("sex"));
					s.setSid(next.getInteger("sid"));
					// 参数1 Json 字符串
					// 参数2 需要的对象的类型
//					String json = next.toJson();
//					System.out.println(json);
//					Student s = gson.fromJson(json, Student.class);
					slist.add(s);
				}
				for(Student ss : slist){
					System.out.println(ss);
				}
				mc.close();
	}
}