[[oktatas:programozas:java:java adatbázis:mongodb|< MongoDB]]

====== MongoDB kezdés ======

  * **Szerző:** Sallai András
  * Copyright (c) 2023, Sallai András
  * Szerkesztve: 2024
  * Licenc: [[https://creativecommons.org/licenses/by-sa/4.0/|CC BY-SA 4.0]]
  * Web: https://szit.hu

===== Adatbázisok =====


<code java>
String url = "mongodb://root:titok@localhost:27017";
            
ConnectionString cs = new ConnectionString(url);
MongoClient client = MongoClients.create(cs);
client.listDatabaseNames().forEach(System.out::println);
</code>


Teljes kód:

<code java App.java>
import com.mongodb.ConnectionString;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;

public class App {
    public static void main(String[] args) throws Exception {
        try {
            String url = "mongodb://root:titok@localhost:27017";
                        
            ConnectionString cs = new ConnectionString(url);
            MongoClient client = MongoClients.create(cs);
            client.listDatabaseNames().forEach(System.out::println);
        } catch (MongoException e) {
            System.err.println("Hiba! A kapcsolódás sikertelen!");
            System.err.println(e.getMessage());
        }
        
    }
}
</code>

===== Gyűjtemények =====

<code java>
String url = "mongodb://root:titok@localhost:27017";
            
ConnectionString cs = new ConnectionString(url);
MongoClient client = MongoClients.create(cs);
MongoDatabase database = client.getDatabase("zoldzrt");
database.listCollectionNames().forEach(System.out::println);
</code>

Teljes kód:

<code java App.java>
import com.mongodb.ConnectionString;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoDatabase;

public class App {
    public static void main(String[] args) throws Exception {
        try {
            String url = "mongodb://root:titok@localhost:27017";
                        
            ConnectionString cs = new ConnectionString(url);
            MongoClient client = MongoClients.create(cs);
            MongoDatabase database = client.getDatabase("zoldzrt");
            database.listCollectionNames().forEach(System.out::println);

        } catch (MongoException e) {
            System.err.println("Hiba! A kapcsolódás sikertelen!");
            System.err.println(e.getMessage());
        }
        
    }
}
</code>

===== Beszúrás =====

<code java>
Document doc = new Document();
doc.put("name", "Erős István");
doc.put("city", "Szeged");
doc.put("salary", 395.2);
collection.insertOne(doc);
</code>


Teljes kód:

<code java App.java>
import org.bson.Document;
import com.mongodb.ConnectionString;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;

public class App {
    public static void main(String[] args) throws Exception {
        try {
            String url = "mongodb://root:titok@localhost:27017";
                        
            ConnectionString cs = new ConnectionString(url);
            MongoClient client = MongoClients.create(cs);
            MongoDatabase database = client.getDatabase("zoldzrt");
            MongoCollection<Document> collection = database.getCollection("employees");

            Document doc = new Document();
            doc.put("name", "Lime Lajos");
            doc.put("city", "Pécs");
            doc.put("salary", 392.8);
            collection.insertOne(doc);

        } catch (MongoException e) {
            System.err.println("Hiba! A kapcsolódás sikertelen!");
            System.err.println(e.getMessage());
        }
        
    }
}

</code>

===== Első =====

<code java>
import org.bson.Document;

import com.mongodb.ConnectionString;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;

public class App {
    public static void main(String[] args) throws Exception {
        try {
            String url = "mongodb://root:titok@localhost:27017";
                        
            ConnectionString cs = new ConnectionString(url);
            MongoClient client = MongoClients.create(cs);
            MongoDatabase database = client.getDatabase("zoldzrt");
            MongoCollection<Document> collection = database.getCollection("employees");

            Document document = collection.find().first();
            System.out.println(document.get("name"));
        } catch (MongoException e) {
            System.err.println("Hiba! A kapcsolódás sikertelen!");
            System.err.println(e.getMessage());
        }
        
    }
}
</code>

===== Program =====

<code java App.java>
import org.bson.Document;

import com.mongodb.ConnectionString;
import com.mongodb.MongoException;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;

public class App {
    public static void main(String[] args) throws Exception {
        try {            
            
            String url = "mongodb://root:titok@localhost:27017";
                        
            ConnectionString cs = new ConnectionString(url);
            MongoClient client = MongoClients.create(cs);
            MongoDatabase database = client.getDatabase("zoldzrt");
            MongoCollection<Document> collection = database.getCollection("employees");

            FindIterable<Document> docs = collection.find();
            docs.forEach(doc -> System.out.println(doc));
        } catch (MongoException e) {
            System.err.println("Hiba! A kapcsolódás sikertelen!);
            System.err.println(e.getMessage());
            System.err.println(e);            
        }
        
    }
}

</code>

===== Link =====

  * https://www.baeldung.com/java-mongodb (2024)