Add Close ability to connection.DB (#66)

db/connection/connection.go

@@ -81,6 +81,8 @@ type ResultFetch func(interface{}) error
 type DB interface {
 	// Clone returns a stateful copy of this connection.
 	Clone() DB
+	// Close does so for all the underlying connections and returns an error if the driver provides one.
+	Close() error
 	// QueryIter returns closure allowing to load/fetch roads one by one.
 	QueryIter(ctx context.Context, statement string, fields []string, args ...interface{}) (ResultFetchIter, error)
 	// EQueryIter is QueryIter but will use EscapeArgs.

db/postgres/connection.go

@@ -111,6 +111,12 @@ func (d *DB) Clone() connection.DB {
 	}
 }
 
+// Close closes the underlying connection, beware, this makes the DB useless.
+func (d *DB) Close() error {
+	d.conn.Close()
+	return nil
+}
+
 // EQueryIter Calls EscapeArgs before invoking QueryIter
 func (d *DB) EQueryIter(ctx context.Context, statement string, fields []string, args ...interface{}) (connection.ResultFetchIter, error) {
 	s, a, err := connection.EscapeArgs(statement, args)

db/postgrespq/connection.go

@@ -105,6 +105,11 @@ func (d *DB) Clone() connection.DB {
 	}
 }
 
+// Close closes the underlying connection, beware, this makes the DB useless.
+func (d *DB) Close() error {
+	return d.conn.Close()
+}
+
 // EQueryIter Calls EscapeArgs before invoking QueryIter
 func (d *DB) EQueryIter(ctx context.Context, statement string, fields []string, args ...interface{}) (connection.ResultFetchIter, error) {
 	s, a, err := connection.EscapeArgs(statement, args)