# Referensi Cepat MongoDB

*CRUD, query, agregasi, indeks, desain schema*

> Source: MongoDB Documentation (mongodb.com/docs) · MIT

## Koneksi

### Connection String

```
mongosh "mongodb://localhost:27017"
mongosh "mongodb://user:pass@host:27017/mydb"
mongosh "mongodb+srv://user:pass@cluster.mongodb.net/mydb"
```

### Koneksi Driver (Node.js)

```
const { MongoClient } = require('mongodb');
const client = new MongoClient(uri);
await client.connect();
const db = client.db('mydb');
```

## Database & Collection

### Operasi Database

```
show dbs
use mydb
db.dropDatabase()
```

### Operasi Collection

```
db.createCollection("users")
show collections
db.users.drop()
```

### Capped Collection

```
db.createCollection("logs", {
  capped: true, size: 10485760, max: 5000
})
```

## Operasi CRUD

### Insert

```
db.users.insertOne({ name: "Alice", age: 30 })
db.users.insertMany([
  { name: "Bob", age: 25 },
  { name: "Carol", age: 28 }
])
```

### Find

```
db.users.findOne({ name: "Alice" })
db.users.find({ age: { $gte: 25 } })
db.users.find({}, { name: 1, _id: 0 })
db.users.find().sort({ age: -1 }).limit(10)
```

### Update

```
db.users.updateOne(
  { name: "Alice" },
  { $set: { age: 31, city: "Boston" } }
)
db.users.updateMany(
  { active: false },
  { $set: { archived: true } }
)
```

### Delete

```
db.users.deleteOne({ name: "Alice" })
db.users.deleteMany({ active: false })
```

### Replace & Upsert

```
db.users.replaceOne(
  { name: "Alice" },
  { name: "Alice", age: 32, city: "NYC" }
)
db.users.updateOne(
  { email: "a@ex.com" },
  { $set: { name: "Alice" } },
  { upsert: true }
)
```

## Operator Query

### Perbandingan

| Command | Description |
|---------|-------------|
| `$eq / $ne` | Sama dengan / tidak sama dengan |
| `$gt / $gte` | Lebih dari / lebih dari atau sama dengan |
| `$lt / $lte` | Kurang dari / kurang dari atau sama dengan |
| `$in / $nin` | Ada dalam array / tidak ada dalam array |

### Logika

| Command | Description |
|---------|-------------|
| `$and` | Semua kondisi harus cocok |
| `$or` | Setidaknya satu kondisi cocok |
| `$not` | Negasi kondisi |
| `$exists` | Field ada (true/false) |
| `$regex` | Kecocokan ekspresi reguler |

### Operator Update

| Command | Description |
|---------|-------------|
| `$set` | Atur nilai field |
| `$unset` | Hapus field |
| `$inc` | Tambah nilai numerik |
| `$push / $pull` | Tambah / hapus elemen array |
| `$addToSet` | Tambah ke array jika belum ada |
| `$rename` | Ganti nama field |

## Agregasi

### Tahap Pipeline

| Command | Description |
|---------|-------------|
| `$match` | Filter dokumen (seperti WHERE) |
| `$group` | Kelompokkan dan agregasi |
| `$project` | Ubah bentuk dokumen (seperti SELECT) |
| `$sort` | Urutkan hasil |
| `$limit / $skip` | Pagination |
| `$lookup` | Left outer join dengan collection lain |
| `$unwind` | Dekonstruksi array menjadi dokumen |

### Contoh Agregasi

```
db.orders.aggregate([
  { $match: { status: "completed" } },
  { $group: {
      _id: "$customer_id",
      total: { $sum: "$amount" },
      count: { $sum: 1 }
  }},
  { $sort: { total: -1 } },
  { $limit: 10 }
])
```

## Indeks

### Buat & Hapus

```
db.users.createIndex({ email: 1 }, { unique: true })
db.users.createIndex({ name: 1, age: -1 })
db.users.createIndex({ location: "2dsphere" })
db.users.dropIndex("email_1")
```

### Tipe Indeks

| Command | Description |
|---------|-------------|
| `Single field` | Indeks pada satu field ({ name: 1 }) |
| `Compound` | Beberapa field ({ a: 1, b: -1 }) |
| `Text` | Pencarian teks penuh ({ field: 'text' }) |
| `2dsphere` | Query geospasial |
| `TTL` | Auto-expire dokumen setelah waktu tertentu |

### Info Indeks

```
db.users.getIndexes()
db.users.find({ name: "Alice" }).explain()
```

## Desain Schema

### Embedding vs Referencing

| Command | Description |
|---------|-------------|
| `Embed` | 1:1 atau 1:sedikit, data dibaca bersama |
| `Reference` | 1:banyak, data diakses secara independen |
| `Embed` | Sub-dokumen jarang melebihi 16 MB |
| `Reference` | Relasi banyak-ke-banyak |

### Validasi Schema

```
db.createCollection("users", {
  validator: { $jsonSchema: {
    bsonType: "object",
    required: ["name", "email"],
    properties: {
      name: { bsonType: "string" },
      email: { bsonType: "string" }
}}}})
```

## Replikasi

### Konsep Replica Set

| Command | Description |
|---------|-------------|
| `Primary` | Menerima semua penulisan |
| `Secondary` | Mereplikasi dari primary, bisa melayani pembacaan |
| `Arbiter` | Memilih dalam pemilihan, tidak menyimpan data |

### Perintah Replica Set

```
rs.initiate()
rs.add("mongo2:27017")
rs.addArb("mongo3:27017")
rs.status()
rs.conf()
```

## Pola Umum

### Transaksi

```
const session = client.startSession();
session.startTransaction();
await db.collection("accounts").updateOne(
  { _id: 1 }, { $inc: { bal: -100 } }, { session });
await db.collection("accounts").updateOne(
  { _id: 2 }, { $inc: { bal: 100 } }, { session });
await session.commitTransaction();
```

### Bulk Write

```
db.users.bulkWrite([
  { insertOne: { document: { name: "Dan" } } },
  { updateOne: {
      filter: { name: "Alice" },
      update: { $set: { age: 31 } }
  }},
  { deleteOne: { filter: { name: "old" } } }
])
```

### Change Stream

```
const stream = db.collection("orders")
  .watch([{ $match: { "fullDocument.status": "new" } }]);
stream.on("change", (change) => {
  console.log(change.fullDocument);
});
```

## Perintah mongosh

### Helper Shell

| Command | Description |
|---------|-------------|
| `show dbs` | Daftar database |
| `show collections` | Daftar collection di db saat ini |
| `db.stats()` | Statistik database |
| `db.collection.stats()` | Statistik collection |
| `db.collection.countDocuments({})` | Hitung dokumen |
| `db.collection.distinct('field')` | Nilai berbeda untuk sebuah field |

### Export & Import

```
mongoexport --db=mydb --collection=users \
  --out=users.json
mongoimport --db=mydb --collection=users \
  --file=users.json
mongodump --db=mydb --out=/backup/
mongorestore --db=mydb /backup/mydb/
```