HAVING clause

SQL HAVING Bayonoti

HAVING bayonoti SQL ga qo'shilgan, chunki WHERE kalit so'zi agregat funksiyalar bilan ishlatilmaydi.

HAVING Sintaksisi

SELECT column_name(s)
FROM table_name
WHERE condition
GROUP BY column_name(s)
HAVING condition
ORDER BY column_name(s);

Demo Ma'lumotlar Bazasi

Ushbu o'quv qo'llanmada Northwind namunaviy ma'lumotlar bazasidan "Customers" jadvalidan bir tanlov:

SQL HAVING Misollari

Quyidagi SQL bayonoti har bir mamlakatdagi mijozlar sonini ro'yxatga oladi. Faqat 5 dan ortiq mijozga ega mamlakatlarni qo'shadi:

SELECT COUNT(CustomerID), Country
FROM Customers
GROUP BY Country
HAVING COUNT(CustomerID) > 5;

Quyidagi SQL bayonoti har bir mamlakatdagi mijozlar sonini yuqoridan pastga tartibda ro'yxatga oladi (faqat 5 dan ortiq mijozga ega mamlakatlar):

SELECT COUNT(CustomerID), Country
FROM Customers
GROUP BY Country
HAVING COUNT(CustomerID) > 5
ORDER BY COUNT(CustomerID) DESC;

Demo Ma'lumotlar Bazasi

Ushbu o'quv qo'llanmada Northwind namunaviy ma'lumotlar bazasidan "Orders" jadvalidan bir tanlov:

Va "Employees" jadvalidan bir tanlov:

Boshqa HAVING Misollari

Quyidagi SQL bayonoti 10 dan ortiq buyurtma bergan xodimlarni ro'yxatga oladi:

SELECT Employees.LastName, COUNT(Orders.OrderID) AS NumberOfOrders
FROM (Orders
INNER JOIN Employees ON Orders.EmployeeID = Employees.EmployeeID)
GROUP BY LastName
HAVING COUNT(Orders.OrderID) > 10;

Quyidagi SQL bayonoti "Davolio" yoki "Fuller" xodimlari 25 dan ortiq buyurtma berganligini ro'yxatga oladi:

SELECT Employees.LastName, COUNT(Orders.OrderID) AS NumberOfOrders
FROM Orders
INNER JOIN Employees ON Orders.EmployeeID = Employees.EmployeeID
WHERE LastName = 'Davolio' OR LastName = 'Fuller'
GROUP BY LastName
HAVING COUNT(Orders.OrderID) > 25;