OQL Group by Clause

The GROUP BY clause will condense all returned rows into a single row that shares the same values for the expressions defined in this clause. The expressions in this clause must exist in the SELECT clause of the query. All expressions in the SELECT clause which do not exist in the GROUP BY clause must be either an aggregation or the result an aggregate function.

The syntax is as following:

GROUP BY
    expression [ ,...n ]

[HAVING <constraint>]

expression Specifies the expressions by which values of the rows are grouped.

HAVING <constraint> Specifies a constraint. When a GROUP BY expression is used, constraints must be defined in a HAVING clause.

SELECT COUNT(Sales.Customer/*)
FROM Sales.Customer
INNER JOIN Sales.Customer/Sales.Customer_Address/Sales.Address
GROUP BY Sales.Address/City

SELECT SUM(Sales.Order/TotalPrice)
FROM Sales.Order
INNER JOIN Sales.Order/Sales.Customer_Order/Sales.Customer/Sales.Customer_Address/Sales.Address
GROUP BY Sales.Address/City

SELECT SUM(Sales.Order/TotalPrice)
FROM Sales.Order
INNER JOIN Sales.Order/Sales.Customer_Order/Sales.Customer/Sales.Customer_Address/Sales.Address
GROUP BY Sales.Address/City
HAVING SUM(Sales.Order/TotalPrice) > 1000.0 OR Sales.Address/City = 'Losdun'