26. Kommunal: ko'rsatkichi kiritilmagan hisoblagichlar
OsonHisoblagichlar meters jadvalida.
Oxirgi ko'rsatkichi kiritilmagan (last_reading — NULL) hisoblagichlarning
meter_code, address, meter_type ustunlarini qaytaring.
⚠️ Diqqat: ko'rsatkichi 0 bo'lgan hisoblagich — bu kiritilgan ko'rsatkich,
u natijaga kirmaydi. NULL va 0 — bir xil narsa emas.
Natijani meter_code bo'yicha alifbo tartibida saralang.
Jadval: meters
| Ustun | Turi |
|---|---|
| id | INT PK |
| meter_code | VARCHAR |
| address | VARCHAR |
| meter_type | VARCHAR |
| last_reading | INT NULL |
Namuna ma'lumotlar
sample-basic
meters
| idINT | meter_codeVARCHAR(20) | addressVARCHAR(100) | meter_typeVARCHAR(20) | last_readingINT |
|---|---|---|---|---|
| 1 | EL-001 | Chilonzor 1 | electric | NULL |
| 2 | WT-002 | Yunusobod 5 | water | 1200 |
| 3 | GS-003 | Yakkasaroy 3 | gas | NULL |
| 4 | HT-004 | Mirzo 7 | heat | 0 |
Kutilgan natija
| address | meter_code | meter_type |
|---|---|---|
| Chilonzor 1 | EL-001 | electric |
| Yakkasaroy 3 | GS-003 | gas |
sample-all-null
meters
| idINT | meter_codeVARCHAR(20) | addressVARCHAR(100) | meter_typeVARCHAR(20) | last_readingINT |
|---|---|---|---|---|
| 1 | A-1 | Addr1 | electric | NULL |
| 2 | A-2 | Addr2 | water | NULL |
Kutilgan natija
| address | meter_code | meter_type |
|---|---|---|
| Addr1 | A-1 | electric |
| Addr2 | A-2 | water |
sample-none-null
meters
| idINT | meter_codeVARCHAR(20) | addressVARCHAR(100) | meter_typeVARCHAR(20) | last_readingINT |
|---|---|---|---|---|
| 1 | B-1 | Addr1 | gas | 500 |
| 2 | B-2 | Addr2 | heat | 0 |
O'xshash masalalar
Konsol
Natijani ko'rish uchun so'rovni ishga tushiring.