SQL GROUP BY Statement

SQL GROUP BY Statement : SQL GROUP BY Statement is often used with aggregate functions (COUNT, MAX, MIN, SUM, AVG) to group the result-set by one or more columns.

GROUP BY Syntax

SELECT column_name(s)
FROM table_name
WHERE condition
GROUP BY column_name(s)
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 GROUP BY Examples

The following SQL statement lists the number of customers in each country:

Example

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

 

Output

Number of Records: 21

COUNT(CustomerID)	Country
3	Argentina
2	Austria
2	Belgium
9	Brazil
3	Canada
2	Denmark
2	Finland
11	France
11	Germany
1	Ireland
3	Italy
5	Mexico
1	Norway
1	Poland
2	Portugal
5	Spain
2	Sweden
2	Switzerland
7	UK
13	USA
4	Venezuela

 

The following SQL statement lists the number of customers in each country, sorted high to low:

Example

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

 

Output

Number of Records: 21

COUNT(CustomerID)	Country
13	USA
11	France
11	Germany
9	Brazil
7	UK
5	Mexico
5	Spain
4	Venezuela
3	Argentina
3	Canada
3	Italy
2	Austria
2	Belgium
2	Denmark
2	Finland
2	Portugal
2	Sweden
2	Switzerland
1	Ireland
1	Norway
1	Poland

 

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 “Shippers” table:

ShipperID	ShipperName
1	Speedy Express
2	United Package
3	Federal Shipping

GROUP BY With JOIN Example

The following SQL statement lists the number of orders sent by each shipper:

Example

SELECT Shippers.ShipperName, COUNT(Orders.OrderID) ASNumberOfOrders FROM Orders
LEFT JOIN Shippers ON Orders.ShipperID = Shippers.ShipperID
GROUP BY ShipperName;

 

Output

Number of Records: 3

ShipperName	NumberOfOrders
Federal Shipping	68
Speedy Express	54
United Package	74