More MongoDB basics

3.0/docs/databases/mongodb/basics.md

@@ -55,6 +55,11 @@ struct User: Codable {
     var _id = ObjectId()
     var username: String
     var age: Int
+
+    init(named name: String, age: Int) {
+        self.username = named
+        self.age = age
+    }
 }
 
 let users = database["users"].map(to: User.self)
@@ -96,6 +101,7 @@ There is also `findOne`, which is useful when you want to exactly one object. Th
 The filter is a MongoKitten [`Query`](query.md) object.
 
 ```swift
+// User?
 guard let joannis = users.findOne("username" == "Joannis" && "active" == true) else {
     return
 }
@@ -107,9 +113,10 @@ A range is any native swift Range. It is used for `skip` and `limit`.
 
 ```swift
 // Cursor with the first 10 users
-let users1 = users.find(in: ..<10)
-let users2 = users.find(in: 10..<20)
-let users3 = users.find(in: 30...)
+
+let users1 = users.find(in: ..<10) // Cursor<User>
+let users2 = users.find(in: 10..<20) // Cursor<User>
+let users3 = users.find(in: 30...) // Cursor<User>
 ```
 
 ### Sort
@@ -117,7 +124,7 @@ let users3 = users.find(in: 30...)
 The [`Sort`](sort.md) is used to sort entities in either ascending or descending order based on one or more fields.
 
 ```swift
-let maleUsers = users.find("gender" == "male", sortedBy: ["age": .ascending])
+let maleUsers = users.find("gender" == "male", sortedBy: ["age": .ascending]) // Cursor<User>
 ```
 
 ### Projection
@@ -125,7 +132,66 @@ let maleUsers = users.find("gender" == "male", sortedBy: ["age": .ascending])
 The [projection](projection.md) ensures only the specifies subset of fields are returned. Projections can also be computed fields. Remember that the projection must fit within the Collection's Codable type. If this is not a dictionary(-like) type such as `Document` it will be required that the Document fetched matches the Codable type.
 
 ```swift
-let adults = users.find("age" >= 21, projecting: ["_id": .excluded, "username": .included])
+let adults = users.find("age" >= 21, projecting: ["_id": .excluded, "username": .included]) // Cursor<User>
+```
+
+## Count
+
+Count is similar to a find operation in that it is a read-only operation. Since it does not return the actual data (only an integer of the total entities found) it does not support projections and sorting. It does support a range expression, although it's not often used.
+
+```swift
+let totalUsers = users.count() // Future<Int>
+let femaleUsers = users.count("gender" == "female") // Future<Int>
+```
+
+## Update
+
+Updating can be done on one or all entities. Updates can either update the entire entity or only a subset of fields.
+
+```swift
+let user = User(named: "Joannis", age: 111)
+
+users.update("username" == "Joannis", to: user)
+```
+
+Update also indicates a success state in the same way `insert` does.
+
+### Updating fields
+
+Updating a subset of fields can be done more efficiently using
+
+```swift
+// Rename `Joannis` -> `JoannisO`
+users.update("username" == "Joannis", fields: [
+    "username": "JoannisO"
+])
+
+// Migrate all users to require a password update
+users.update(fields: [
+    "resetPassword": true
+])
+```
+
+### Upsert
+
+If you don't know if an entity exists but want it inserted/updated accordingly you should use `upsert`.
+
+```swift
+let user = User(named: "Joannis", age: 111)
+
+users.upsert("_id" == user._id, to: user)
+```
+
+## Remove
+
+Remove removes the first or all entities matching a query.
+
+```swift
+// Remove me!
+users.remove("username" == "Joannis")
+
+// Remove all Dutch users
+users.removeAll("country" == "NL")
 ```
 
 # Troubleshooting