#### Show All Created Databases

```javascript
show dbs
```

#### Starte using the database named `dbname`

```javascript
 use dbname
```

#### Show a collections inside a database

```javascript
show collections
```

#### Delete/Drop a database

```javascript
db.dropDatabase();
```

#### Create database if not exist and start using it

```javascript
use dbname
```

#### Get the current databse

```javascript
db;
```

#### Create a collection named `posts`

```javascript
db.createCollection("posts");
```

#### Insert a post into `posts` collection

```javascript
db.posts.insert({ name: "Shehan", age: 24 });
```

#### Insert many posts into `posts` collection

```javascript
db.posts.insertMany([{}, {}, {}]);
```

#### Get all the posts

```javascript
db.posts.find();
```

#### Show all posts in a pretty way

```javascript
db.posts.find().pretty();
```

#### Sort all posts based on title to Ascending order

```javascript
db.posts.sort({ title: 1 }).pretty();
```

#### Count the number os posts

```javascript
db.posts.find({ category: "news" }).count();
```

#### Get only 2 posts (Limit the number of posts)

```javascript
db.posts
  .find()
  .limit(2)
  .pretty();
```

##### Get only 2 posts from the sorted posts

```javascript
db.posts
  .find()
  .sort({ title: -1 })
  .limit(2)
  .pretty();
```

#### Print all the names of posts

```javascript
db.posts.find().forEach(function(post) {
  print("Post" + post.name);
});
```

#### Get only one post from 'news' category

```javascript
db.posts.findOne({ category: "news" });
```

#### Update a post, if not found, insert it

```javascript
db.posts.update(
  { name: "Shehan" },
  { name: "Shay", age: 24 },
  { upsert: true }
);
```

#### Only update the specific part

```javascript
db.posts.update({ name: "Shehan" }, { $set: { name: "Morgan", isMale: true } });
```

#### Increase age by 2

```javascript
db.posts.update({ name: "Shehan" }, { $inc: { age: 2 } });
```

#### Rename 'age' to 'years'

```javascript
db.posts.update({ name: "Shehan" }, { $rename: { age: years } });
```

#### Remove an instance

```javascript
db.posts.remove({ name: "Shehan" });
```

#### Add sub documents

```javascript
db.posts.update({ name: "Shehan" }, { $set: { skills: ["JavaScript"] } });
```

#### Find a document by sub document

```javascript
db.users.find({ comments: { $elemMatch: { name: "Haily" } } }).pretty();
```

#### Creating an index

```javascript
db.users.createIndex({ username: "text" });
```

#### Searching with Index

```javascript
db.users.find({ $text: { $search: '"Moriah"' } }).pretty();
```

#### Greater than

```javascript
db.users.find({ id: { $gt: 9 } }).pretty();
```

#### Greater than or Equal

```javascript
db.users.find({ id: { $gte: 9 } }).pretty();
```

#### Lesser than

```javascript
db.users.find({ id: { $lt: 9 } }).pretty();
```

#### Lesser than or Equal

```javascript
db.users.find({ id: { $lte: 9 } }).pretty();
```