         XCTAssertEqual(Int(6), results.sum("intCol") as Int)
         XCTAssertEqualWithAccuracy(Float(5.5), results.sum("floatCol") as Float, 0.001)
         XCTAssertEqualWithAccuracy(Double(5.55), results.sum("doubleCol") as Double, 0.001)
+
+        assertThrows(results.sum("noSuchCol") as Float)
     }
 
     func testAverage() {

        XCTAssertEqual(Float(2.2), results.max("floatCol") as Float!)
        XCTAssertEqual(Double(2.22), results.max("doubleCol") as Double!)
        XCTAssertEqual(NSDate(timeIntervalSince1970: 2), results.max("dateCol") as NSDate!)
    }

    func testSum() {

        XCTAssertEqual(2.22, sorted[1].doubleCol)
        XCTAssertEqual(2, sorted[1].intCol)
        XCTAssertEqual(1.11, sorted[2].doubleCol)

        assertThrows(results.sorted([SortDescriptor(property: "noSuchCol")]))
    }

    func testMin() {
