Ma’lumotlar tahlili yo‘nalishi bo‘yicha o‘qituvchilar uchun qo‘llanma

1- yechim:

SELECT billingcountry, count(invoicedate) AS Invoices

FROM Invoice GROUP BY billingcountry

ORDER BY Invoices DESC;

2- yechim:

SELECT Invoice.BillingCountry, COUNT(Invoice.BillingCountry)

FROM Invoice

GROUP BY Invoice.BillingCountry

ORDER BY COUNT(Invoice.Total) DESC;

2-savol. Biz eng ko‘p pul ishlagan shaharda reklama musiqiy festivalini o‘tkazmoqchimiz. Hisob-fakturalar summasi eng ko‘p bo‘lgan shaharni qaytaradigan so‘rov yozing. Shahar nomini va barcha hisob-fakturalar summasini qaytaring.

Ikkinchi savolga mos so’rov yozish uchun uni tahlil qilaylik va qaysi jadvaldan foydalanish kerakligini o’ylab ko’raylik. Shaharni tanlash uchun SELECTdan so’ng billingcityni yozamiz. Eng ko’p pul ishlaganlarni topish uchun MAX() ni ishlatamiz. Shahar nomini va barcha invoicelarni qaytarish uchun ikkinchi SELECTdan foydalanamiz. Natija quyidagicha bo’ladi.