I have 2 Tables, units & unitImages, when I JOIN the tables and ORDER BY unitImages.list_unitImages, I get the following (1), but I have been trying to GROUP BY units.id_unit with the ORDER BY unitImages.list_unitImages (2) but for some reason I get for list_unitImages 17 instead of 16 which is the first on the list, I have add other images under other units and it still skips the first row.
(1)
SELECT units.id_unit, units.name_unit, unitImages.list_unitImages, unitImages.file_unitImages
FROM (units LEFT JOIN unitImages ON unitImages.idpar_unitImages=units.id_unit)
ORDER BY unitImages.list_unitImages

id_unit name_unit list_unitImages file_unitImages
3 Test Room 3 12 Balcony10_1_1.jpg
4 Unit 4 13 Ilsa BedroomMaster One_1_1.jpg
5 Unit 5 14 Mask05_1_1.jpg
1 Suite 408/407 16 Balcony08_2.jpg
1 Suite 408/407 17 HotelBathRoom2.jpg
1 Suite 408/407 18 HotelBathRoom1.jpg

(2)
SELECT units.id_unit, units.name_unit, unitImages.list_unitImages, unitImages.file_unitImages
FROM (units LEFT JOIN unitImages ON unitImages.idpar_unitImages=units.id_unit)
GROUP BY units.id_unit
ORDER BY unitImages.list_unitImages
id_unit name_unit list_unitImages file_unitImages
3 Test Room 3 12 Balcony10_1_1.jpg
4 Unit 4 13 Ilsa BedroomMaster One_1_1.jpg
5 Unit 5 14 Mask05_1_1.jpg
1 Suite 408/407 17 HotelBathRoom2.jpg