SQL vazifa to'plami 4.2 Darajasi
Quyidagi jadval berilgan:
| id | total_amount | order_date | ship_date | customer_id |
| 1 | 500.10 | 2023-10-10 | 2023-10-12 | 5 |
| 2 | 321.50 | 2023-10-15 | 2023-10-19 | 5 |
| 3 | 201.15 | 2023-10-13 | 2023-10-14 | 5 |
| 4 | 554.12 | 2023-10-01 | 2023-10-03 | 3 |
| 5 | 321.77 | 2023-10-15 | 2023-10-17 | 2 |
| 6 | 222.11 | 2023-10-20 | 2023-10-21 | 3 |
| 7 | 312.41 | 2023-10-19 | 2023-10-21 | 2 |
| 8 | 290.30 | 2023-10-15 | 2023-10-20 | 3 |
| 9 | 740.10 | 2023-10-11 | 2023-10-20 | 4 |
| 10 | 100.60 | 2023-10-12 | 2023-10-21 | 4 |
Uchun quyidagi masalalarni yeching:
Buyurtmalarni mijozlar bo'yicha guruhlaydigan va har bir mijoz uchun buyurtmalarning umumiy summasini chiqaradigan so'rov yozing.
Buyurtmalarni mijozlar bo'yicha guruhlaydigan va har bir mijoz uchun o'rtacha buyurtma hajmini hisoblaydigan so'rov yozing.
Har bir mijoz uchun o'rtacha yetkazib berish muddatini hisoblaydigan so'rov yozing.
Eng ko'p buyurtma qaysi hafta kunlarida berilishini aniqlash uchun buyurtmalarni hafta kunlari bo'yicha guruhlaydigan so'rov yozing.
