Group by va order by standart so‘zlaridan foydalanib so’rov yaratish. Order by

GROUP BY va ORDER BY

standart so‘zlaridan foydalanib so’rov yaratish.

ORDER BY operatori qiymatlarni bir yoki bir nechta ustunlar bo'yicha saralaydi. ORDER BY operatori sintaksisi quyidagicha:

SELECT

select_list

FROM

table_name

ORDER BY

column1 [ASC|DESC],

column2 [ASC|DESC],

...;

ASC kalit so’zi ustunni o’sish tartibida saralashni, DESC esa kamayish tartibida saralashni bildiradi. Odatiy qiymat ASC.

Natijaviy to’plamni column1 ustuni bo’yicha o’sish tartibida saralash:

ORDER BY column1 ASC;

Yoki

ORDER BY column1;

Natijaviy to’plamni column1 ustuni bo’yicha o’sish tartibida saralash:

ORDER BY column1 DESC;

ORDER BY operatori SELECT va FROM operatorlaridan so’ng bajariladi:

Familiya ustuni bo’yicha saralash:

SELECT

contactLastname,

contactFirstname

FROM

customers

ORDER BY

contactLastname;

Familiya ustuni bo’yicha kamayish tartibida saralash:

SELECT

contactLastname,

contactFirstname

FROM

customers

ORDER BY

contactLastname DESC;

Saralashni ifoda orqali amalga oshirish:

SELECT

orderNumber,

orderlinenumber,

quantityOrdered * priceEach

FROM

orderdetails

ORDER BY

quantityOrdered * priceEach DESC;

GROUP BY operatori qatorlar to'plamini ustunlar yoki ifodalar qiymatlari bo'yicha natijaviy qatorlar to'plamiga guruhlaydi. GROUP BY operatori har bir guruh uchun bitta qatorni qaytaradi. Boshqacha qilib aytganda, natijalar to'plamidagi qatorlar sonini kamaytiradi.

GROUP BY operatori ko’pincha agregat funksiyalar bilan ishlatiladi. GROUP BY operatori sintaksisi quyidagicha:

SELECT

c1, c2,..., cn, aggregate_function(ci)

FROM

table

WHERE

where_conditions

GROUP BY c1 , c2,...,cn;

GROUP BY operatori bajarilish o’rni:

GROUP BY operatori bilan agregat funksiyalarning ishlatishiga misol: