add database files

.gitignore

@@ -1,7 +1,5 @@
 Packages
 .build
-
-Database
-
 .DS_Store
 *.xcodeproj
+

Sources/Fluent/Database/Database.swift

@@ -0,0 +1,34 @@
+import Foundation
+
+/**
+    References a database with a single `Driver`.
+    Statically maps `Model`s to `Database`s.
+*/
+public class Database {
+    /**
+        The `Driver` powering this database. 
+        Responsible for executing queries.
+    */
+    public let driver: Driver
+
+    /** 
+        Creates a `Database` with the supplied
+        `Driver`. This cannot be changed later.
+    */
+    public init(driver: Driver) {
+        self.driver = driver
+    }
+
+    /**
+        Maps `Model` names to their respective 
+        `Database`. This allows multiple models 
+        in the same application to use different
+        methods of data persistence.
+    */
+    public static var map: [String: Database] = [:]
+
+    /**
+        The default database for all `Model` types.
+    */
+    public static var `default`: Database = Database(driver: PrintDriver())
+}

Sources/Fluent/Database/Driver.swift

@@ -0,0 +1,31 @@
+/**
+    A `Driver` execute queries
+    and returns an array of results.
+    It is responsible for interfacing
+    with the data store powering Fluent.
+*/
+public protocol Driver {
+    /**
+        The string value for the 
+        default identifier key.
+     
+        The `idKey` will be used when
+        `Model.find(_:)` or other find
+        by identifier methods are used.
+    */
+    var idKey: String { get }
+
+    /**
+        Executes a `Query` from and
+        returns an array of results fetched,
+        created, or updated by the action.
+    */
+    @discardableResult
+    func query<T: Model>(_ query: Query<T>) throws -> [[String: Value]]
+
+    /**
+        Creates the `Schema` indicated
+        by the `Builder`.
+    */
+    func schema(_ schema: Schema) throws
+}

Sources/Fluent/Database/PrintDriver.swift

@@ -0,0 +1,28 @@
+/**
+    A dummy `Driver` useful for developing.
+*/
+public class PrintDriver: Driver {
+    public var idKey: String = "foo"
+
+    public func query<T: Model>(_ query: Query<T>) throws -> [[String : Value]] {
+
+        let sql = SQL(query: query)
+        let serializer = GeneralSQLSerializer(sql: sql)
+
+        let (statement, values) = serializer.serialize()
+        print("[Print driver]")
+
+        print("Statement: \(statement) Values: \(values)")
+
+        print("Table \(query.entity)")
+        print("Action \(query.action)")
+        print("Filters \(query.filters)")
+        print()
+
+        return []
+    }
+
+    public func schema(_ schema: Schema) throws {
+        //let sql = SQL(builder: builder)
+    }
+}

Sources/Fluent/Query/Query.swift

@@ -49,7 +49,7 @@ public class Query<T: Model> {
         Creates a new `Query` with the
         `Model`'s database.
     */
-    init() {
+    public init() {
         filters = []
         action = .fetch
         database = T.database