     }
 
     func testFilterFormat() {
+        XCTAssertEqual(Int(1), results.filter("stringCol = '1'").count)
         XCTAssertEqual(Int(1), results.filter("stringCol = %@", "1").count)
         XCTAssertEqual(Int(1), results.filter("stringCol = %@", "2").count)
         XCTAssertEqual(Int(0), results.filter("stringCol = %@", "3").count)

        sorted = results.sorted("stringCol", ascending: false)
        XCTAssertEqual("2", sorted[0].stringCol)
        XCTAssertEqual("1", sorted[1].stringCol)
    }

    func testSortWithDescriptor() {

        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() {
