-- 1.1 Nima nima ko'rsatadigan so'rov: SELECT campaign, COUNT(*) as rows, COUNT(DISTINCT co.user_id) AS users FROM campaigns AS ca INNER JOIN communications AS co ON ca.campaign = co.campaign GROUP BY ca.campaign AS campaign -- 1.2 Agar JOIN turini LEFT ga o'zgartirsangiz, javob qanday o'zgaradi? -- 1.3 Bu so'rovda operatorlarning bajarilish tartibini ko'rsating. -- 2. campaigns jadvali tuzatildi: takrorlanishlar olib tashlandi, kalit (PK) qo'shildi. -- Ko'proq kampaniyalar o'tkazildi, xatolar tufayli foydalanuvchilarning yetkazib berish urinishlari muvaffaqiyatsiz bo'ldi, va ba'zilari umuman ko'rsatilmadi. -- Misol 1: communications -- | user_id | campaign | status | -- | 1000001 | promo_cats | error | -- | 1000001 | promo_cats | error | -- | 1000001 | promo_cats | success| -- | 1000001 | promo_cats | success| -- | 1000001 | promo_cats | error | -- Misol 2: communications -- | user_id | campaign | status | -- | 1000002 | promo_rats | error | -- | 1000002 | promo_rats | error | -- | 1000002 | promo_rats | error | -- | 1000002 | promo_rats | error | -- | 1000002 | promo_rats | error | -- Foydalanuvchilarga yuborilgan promo-kampaniyalar haqida: -- 2.1 Har bir kampaniya uchun muvaffaqiyatli olgan foydalanuvchilar sonini chiqaradigan so'rov yozing. -- 2.2 So'rovni o'zgartiring, har bir kampaniya uchun hech qanday muvaffaqiyatli aloqa olmagan foydalanuvchilar sonini chiqarish uchun.