Read Data from MongoDB With Queries

1
using MongoDB.Bson;
2
using MongoDB.Driver;
3

4
// Replace the uri string with your MongoDB deployment's connection string.
5
var uri = "mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority";
6

7
var client = new MongoClient(uri);
8

9
// database and collection code goes here
10
var db = client.GetDatabase("sample_guides");
11
var coll = db.GetCollection<BsonDocument>("planets");
12
// find code goes here
13
var cursor = from planet in coll.AsQueryable()
14
             where planet["hasRings"] == true
15
             select planet;
16
// iterate code goes here
17
foreach (var document in cursor)
18
{
19
    Console.WriteLine(document);
20
}
21

22

1
package main
2
3
import (
4
	"context"
5
	"fmt"
6
7
	"go.mongodb.org/mongo-driver/bson"
8
	"go.mongodb.org/mongo-driver/mongo"
9
	"go.mongodb.org/mongo-driver/mongo/options"
10
)
11
12
func main() {
13
	uri := "mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority"
14
15
	client, err := mongo.Connect(context.TODO(), options.Client().ApplyURI(uri))
16
	if err != nil {
17
		panic(err)
18
	}
19
20
	defer func() {
21
		if err = client.Disconnect(context.TODO()); err != nil {
22
			panic(err)
23
		}
24
	}()
25
26
	// database and colletion code goes here
27
	db := client.Database("sample_guides")
28
	coll := db.Collection("planets")
29
30
	// find code goes here
31
	filter := bson.D{{"hasRings", true}}
32
	cursor, err := coll.Find(context.TODO(), filter)
33
	if err != nil {
34
		panic(err)
35
	}
36
37
	// iterate code goes here
38
	for cursor.Next(context.TODO()) {
39
		var result bson.M
40
		if err := cursor.Decode(&result); err != nil {
41
			panic(err)
42
		}
43
		fmt.Println(result)
44
	}
45
	if err := cursor.Err(); err != nil {
46
		panic(err)
47
	}
48
49
}

1
import com.mongodb.client.*;
2
import com.mongodb.client.model.Filters.*;
3
import org.bson.Document;
4
import org.bson.conversions.Bson;
5
6
public class CrudRead {
7
    public static void main(String[] args) {
8
        String uri = "mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority";
9
10
        try (MongoClient mongoClient = MongoClients.create(uri)) {
11
            // database and collection code goes here
12
            MongoDatabase db = mongoClient.getDatabase("sample_guides");
13
            MongoCollection<Document> coll = db.getCollection("planets");
14
15
            // find code goes here
16
            Bson filter = eq("hasRings", true);
17
            MongoCursor<Document> cursor = coll.find(filter).iterator();
18
19
            // iterate code goes here
20
            try {
21
                while (cursor.hasNext()) {
22
                    System.out.println(cursor.next().toJson());
23
                }
24
            } finally {
25
                cursor.close();
26
            }
27
        }
28
    }
29
}

1
const { MongoClient } = require("mongodb");
2
// Replace the uri string with your MongoDB deployment's connection string.
3
const uri =
4
  "mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority";
5
const client = new MongoClient(uri);
6
async function run() {
7
  try {
8
    await client.connect();
9
    // database and collection code goes here
10
    const db = client.db("sample_guides");
11
    const coll = db.collection("planets");
12
13
    // find code goes here
14
    const cursor = coll.find({ hasRings: true });
15
16
    // iterate code goes here
17
    await cursor.forEach(console.log);
18
  } finally {
19
    // Ensures that the client will close when you finish/error
20
    await client.close();
21
  }
22
}
23
run().catch(console.dir);

1
from pymongo import MongoClient
2
3
# Replace the uri string with your MongoDB deployment's connection string.
4
uri = "mongodb+srv://<user>:<password>@<cluster-url>?retryWrites=true&writeConcern=majority"
5
6
client = MongoClient(uri)
7
8
# database and collection code goes here
9
db = client.sample_guides
10
coll = db.planets
11
# find code goes here
12
cursor = coll.find({"hasRings": True})
13
# iterate code goes here
14
for doc in cursor:
15
    print(doc)
16
17
# Close the connection to MongoDB when you're done.
18
client.close()

1
// find code goes here
2
var cursor = from planet in coll.AsQueryable()
3
             where planet["hasRings"] == false
4
             where planet["mainAtmosphere"] == "Ar"
5
             select planet;

1
// find code goes here
2
filter := bson.D{
3
	{"$and",
4
		bson.A{
5
			bson.D{{"hasRings", false}},
6
			bson.D{{"mainAtmosphere", "Ar"}},
7
		},
8
	},
9
}
10
cursor, err := coll.Find(context.TODO(), filter)
11
if err != nil {
12
	panic(err)
13
}

1
// find code goes here
2
Bson filter = and(eq("hasRings", false), eq("mainAtmosphere", "Ar"));
3
MongoCursor<Document> cursor = coll.find(filter).iterator();

1
// find code goes here
2
const cursor = coll.find({ hasRings: false, mainAtomsphere: "Ar" });

1
# find code goes here
2
cursor = coll.find({"hasRings": False, "mainAtmosphere": "Ar"})