JAVA如何操作MongoDB？
MongoDB的数据库、集合(表)的创建、增删改查的基本操作
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一、为两方建立起沟通的桥梁
Java链接MongoDB
1-- 导入MongoDB驱动包
2--- 新建类，获取链接对象
MongoClient mongoClient = new MongoClient("localhost",27017);3--- 关闭链接
mongoClient.close();二、如何查看数据库、集合
1、查看链接MongoDB的数据库
public class getDatas {
public static void main(String[] args) {
//获取Mongo的链接对象
MongoClient mongoClient = new MongoClient("localhost",27017);
//获取库对象
MongoDatabase database = mongoClient.getDatabase("myhahaha");
//查看链接的MongoDB中的所有的库
MongoIterable<String> listCollectionNames = database.listCollectionNames();
for(String st:listCollectionNames) {
System.out.println(st);
}
}
}在MongoDB中创建的数据库（如下图）:
2、使用MongoDB中的库查看库中的集合
public class GetCollectionDemo {
public static void main(String[] args) {
//获取Mongo的链接对象
MongoClient mongoClient = new MongoClient("localhost",27017);
//获取库对象
MongoDatabase mongoDatabase = mongoClient.getDatabase("myhahaha");
//获取表对象
MongoCollection<Document> collection = mongoDatabase.getCollection("student");
//全查 Document文档的集合
FindIterable<Document> find = collection.find();
//迭代器对象 Cursor游标就是迭代器
MongoCursor<Document> iterator = find.iterator();
//遍历取值
while(iterator.hasNext()) {
Document next = iterator.next();
System.out.println(next);
}
//关闭链接
mongoClient.close();
}
}在MongoDB中创建的数据库（如下图）:
3、获取单独的某一个库的对象 和 库中所有的集合的操作（表）
public class GetCollectionDemo {
public static void main(String[] args) {
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
System.out.println(db);
// 获取库中的表的集合
MongoIterable<String> listcollnames = db.listCollectionNames();
// 表的迭代器对象
MongoCursor<String> iterator = listcollnames.iterator();
while(iterator.hasNext()) {
System.out.println(iterator.next());
}
mc.close();
}
}三、进行数据库的增删改查功能
【一】新增
1、新增一条数据
public class documentTest {
public static void main(String[] args) {
//创建一个类对象
Student su = new Student();
su.setSbirthday(new Date());
su.setSclassid(007);
su.setSid(2);
su.setSname("阿里");
su.setSsex("男");
//获取Mongo的链接对象
MongoClient mongoClient = new MongoClient("localhost",27017);
//获取库对象
MongoDatabase mongoDatabase = mongoClient.getDatabase("myhahaha");
//获取表对象
MongoCollection<Document> table = mongoDatabase.getCollection("student");
//创建一个document 文档 对象
Document document = new Document();
document.put("sid", su.getSid());
document.put("sbirthday", su.getSbirthday());
document.put("sclassid", su.getSclassid());
document.put("sname", su.getSname());
document.put("ssex", su.getSsex());
//新增一条数据
table.insertOne(document);
//关闭链接
mongoClient.close();
}
}2、新增多条数据
public static void main(String[] args) {
// 新建对象设置数值
Student s = new Student();
s.setBirthday(new Date());
s.setClassid(100);
s.setSid(1);
s.setSname("张三");
s.setSsex("男");
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
// 创建多个document对象
Document doc = new Document();
doc.put("sid", s.getSid());
doc.put("sname", s.getSname());
doc.put("birthday", s.getBirthday());
doc.put("ssex", s.getSsex());
doc.put("classid", s.getClassid());
Document doc2 = new Document();
doc2.put("sid", 2);
doc2.put("sname", "李四");
doc2.put("birthday", new Date());
doc2.put("ssex", "女");
doc2.put("classid", 200);
Document doc3 = new Document();
doc3.put("sid", 3);
doc3.put("sname", "王五");
doc3.put("birthday", new Date());
doc3.put("ssex", "男");
doc3.put("classid", 300);
//创建集合
List<Document> dlist = new ArrayList<Document>();
dlist.add(doc);
dlist.add(doc2);
dlist.add(doc3);
// 插入多条数据
table.insertMany(dlist);
// 释放资源
mc.close();
}
}
【二】 删除
1.删除单个数据
public class DeleteStudentDemo {
public static void main(String[] args) {
// Mongo操作
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
Bson eq = Filters.eq("sname", "哈哈");
DeleteResult deleteOne = table.deleteOne(eq);
if(deleteMany.getDeletedCount() > 0) {
System.out.println("删除成功");
}else {
System.out.println("删除失败");
}
mc.close();
}
}
2.删除多个数据
public class DeleteStudentDemo {
public static void main(String[] args) {
// Mongo操作
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
Bson eq = Filters.eq("sname", "哈哈");
DeleteResult deleteMany = table.deleteMany(eq);
System.out.println(deleteMany.getDeletedCount());
if(deleteMany.getDeletedCount() > 0) {
System.out.println("删除成功");
}else {
System.out.println("删除失败");
}
mc.close();
}
}
【三】修改
1.修改一条数据
public class UpdateStudent{
public static void main(String[] args) {
// Mongo操作
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
// 条件对象 where ssex = 男 and (classid = 1 or classid = 2)
Bson eq = Filters.and(
Filters.eq("ssex", "男"),
Filters.or(
Filters.eq("classid", 1),
Filters.eq("classid", 2)
)
);
// 要修改的数据
Document doc = new Document();
doc.put("$set", new Document("sname","哈哈"));
UpdateResult updateOne = table.updateOne(eq, doc);
System.out.println(updateOne);
mc.close();
}
}2.修改多条数据
public class UpdateStudentDemo {
public static void main(String[] args) {
// Mongo操作
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
// 条件对象 where ssex = 男 and (classid = 1 or classid = 2)
Bson eq = Filters.and(
Filters.eq("ssex", "男"),
Filters.or(
Filters.eq("classid", 1),
Filters.eq("classid", 2)
)
);
// 要修改的数据
Document doc = new Document();
doc.put("$set", new Document("sname","哈哈"));
UpdateResult updateMany = table.updateMany(eq, doc);
System.out.println(updateMany);
mc.close();
}
}
【四】查询
1、排序查询
public class FindStudentDemo {
public static void main(String[] args) {
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
//排序查询，1~表示升序;-1~表示降序
Document document = new Document("classid",-1);
FindIterable<Document> find = table.find().sort(document);
for(Document doc : find) {
System.out.println(doc);
}
mc.close();
}
}
2、使用正则表达式进行模糊查询
public class FindStudentDemo {
public static void main(String[] args) {
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
//使用正则表达式进行模糊查询
Bson bson = Filters.regex("sname", "帅");
FindIterable<Document> find = table.find(bson);
MongoCursor<Document> iterator = find.iterator();
for(Document doc : find) {
System.out.println(doc);
}
mc.close();
}
3、全查
public class FindStudentDemo {
public static void main(String[] args) {
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
FindIterable<Document> find = table.find();
MongoCursor<Document> iterator = find.iterator();
for(Document doc : find) {
System.out.println(doc);
}
mc.close();
}
4.分页查询
public class FindStudentDemo {
public static void main(String[] args) {
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
// 跳转，分页
FindIterable<Document> bbs =table.find().skip(2).limit(3);
MongoCursor<Document> iterator = bbs.iterator();
for(Document doc : find) {
System.out.println(doc);
}
mc.close();
}
}
5.带条件查询
public class FindStudentDemo {
public static void main(String[] args) {
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
Bson b1 = Filters.eq("Sname","张三");
FindIterator<Document> bbs = table.find(b1)
MongoCursor<Document> iterator = bbs.iterator();
for(Document doc : find) {
System.out.println(doc);
}
mc.close();
}
}6.带多个条件查询
public class FindStudentDemo {
public static void main(String[] args) {
// 获取Mongo的链接对象
MongoClient mc = new MongoClient("localhost", 27017);
// 获取库对象
MongoDatabase db = mc.getDatabase("myschool");
// 获取表对象
MongoCollection<Document> table = db.getCollection("student");
Bson b1 = Filters.and(
Filters.eq("Sname","张三"),
Filters.gte("Classid",100),
);
FindIterator<Document> bbs = table.find(b1)
MongoCursor<Document> iterator = bbs.iterator();
for(Document doc : find) {
System.out.println(doc);
}
mc.close();
}
}
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