SQL WHERE bandi

WHERE bandi yozuvlarni filtrlash uchun ishlatiladi.

WHERE bandi faqat belgilangan shartni qanoatlantiradigan yozuvlarni ajratib olish uchun ishlatiladi.

Bu yerda Mexico davlatidagi barcha mijozlarni tanlaymiz:

SELECT * FROM Customers
WHERE Country = 'Mexico';

WHERE sintaksisi

SELECT column1, column2, ... FROM table_name WHERE condition;

Eslatma: WHERE bandi nafaqat SELECT buyruqlarida, balki UPDATE, DELETE va boshqa buyruqlarda ham ishlatiladi.

Quyida misollarda foydalanilgan Customers jadvalidan tanlanma keltirilgan:

CustomerID	CustomerName	ContactName	Address	City	PostalCode	Country
1	Alfreds Futterkiste	Maria Anders	Obere Str. 57	Berlin	12209	Germany
2	Ana Trujillo Emparedados y helados	Ana Trujillo	Avda. de la Constitución 2222	México D.F.	05021	Mexico
3	Antonio Moreno Taquería	Antonio Moreno	Mataderos 2312	México D.F.	05023	Mexico
4	Around the Horn	Thomas Hardy	120 Hanover Sq.	London	WA1 1DP	UK
5	Berglunds snabbköp	Christina Berglund	Berguvsvägen 8	Luleå	S-958 22	Sweden

SQL matnli qiymatlar atrofida bittalik tirnoq bo‘lishini talab qiladi (ko‘pchilik tizimlar qo‘shtirnoqqa ham ruxsat beradi).

Biroq sonli maydonlar tirnoq ichiga olinmasligi kerak:

SELECT * FROM Customers
WHERE CustomerID = 1;

Qidiruvni filtrlash uchun = operatoridan boshqa operatorlardan ham foydalanishingiz mumkin.

CustomerID qiymati 80 dan katta bo‘lgan barcha mijozlarni tanlash:

SELECT * FROM Customers
WHERE CustomerID > 80;

WHERE shartida quyidagi operatorlardan foydalanish mumkin:

Operator	Tavsif	Misol
=	Equal	Try it
>	Katta	Try it
<	Kichik	Try it
>=	Katta yoki teng	Try it
<=	Kichik yoki teng	Try it
<>	Teng emas. Eslatma: SQL ning ayrim versiyalarida bu operator != sifatida yozilishi mumkin	Try it
BETWEEN	Muayyan oraliqda	Try it
LIKE	Andoza bo‘yicha qidirish	Try it
IN	Ustun uchun bir nechta mumkin bo‘lgan qiymatlarni belgilash uchun	Try it

Yutuqlaringizni kuzating – bu bepul!