# Basic MongoDB Operations

### Queries and Indexes

#### Display query stats

```
db.<collection>.find({<query conditions>}).explain('executionStats')
```

### Basic Document Operations

#### Find all documents in a collection

```
db.<collection>.find({})
```

#### Sorting documents

```
db.<collection>.find({}).sort()
```

#### Find one document in a collection

```
db.<collection>.findOne({})
```

#### Count documents in a collection

```
db.<collection>.count()
```

#### Insert a document

```
db.<collection>.insert({fieldA: 'a', fieldB: 'b'})
```

#### Updating a document

```
db.<collection>.update({_id: '<document id>'}, {'$set': {'fieldA': 'value'}})
```

#### Updating multiple documents

```
db.<collection>.update({<field condition>: '<condition>'}, {'$set': {'fieldA': 'value'}}, {multi: true})
```

#### Delete a document

```
db.<collection>.remove({_id: '<document id>'})
```

### Collection Operations

#### Remove a collection

```
db.<collection>.drop()
```

#### List all collections

```
show collections
```

### Database Operations

#### List all databases

```
show databases
```

#### Switch to a database

```
use <database>
```