SQL HAVING Clause

SQL HAVING Clause : SQL HAVING clause was added to SQL because the WHERE keyword could not be used with aggregate functions.

HAVING Syntax

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

 

Demo Database

Below is a selection from the “Customers” table in the Northwind sample database:

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 HAVING Examples

The following SQL statement lists the number of customers in each country. Only include countries with more than 5 customers:

Example

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

 

Output

Number of Records: 5

COUNT(CustomerID)	Country
9	Brazil
11	France
11	Germany
7	UK
13	USA

 

The following SQL statement lists the number of customers in each country, sorted high to low (Only include countries with more than 5 customers):

Example

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

 

Output

Number of Records: 5

COUNT(CustomerID)	Country
13	USA
11	France
11	Germany
9	Brazil
7	UK

 

Demo Database

Below is a selection from the “Orders” table in the Northwind sample database:

OrderID	CustomerID	EmployeeID	OrderDate	ShipperID
10248	90	5	1996-07-04	3
10249	81	6	1996-07-05	1
10250	34	4	1996-07-08	2

And a selection from the “Employees” table:

EmployeeID	LastName	FirstName	BirthDate	Photo	Notes
1	Davolio	Nancy	1968-12-08	EmpID1.pic	Education includes a BA….
2	Fuller	Andrew	1952-02-19	EmpID2.pic	Andrew received his BTS….
3	Leverling	Janet	1963-08-30	EmpID3.pic	Janet has a BS degree….

 

More HAVING Examples

The following SQL statement lists the employees that have registered more than 10 orders:

Example

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

 

Output

Number of Records: 8

LastName	NumberOfOrders
Buchanan	11
Callahan	27
Davolio	29
Fuller	20
King	14
Leverling	31
Peacock	40
Suyama	18

 

The following SQL statement lists if the employees “Davolio” or “Fuller” have registered more than 25 orders:

Example

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

Output

Number of Records: 1

LastName	NumberOfOrders
Davolio	29