Essential ADO.NET

B.6. Aggregates

The following aggregate types are supported:

Sum (Sum)

Avg (Average)

Min (Minimum)

Max (Maximum)

Count (Count)

StDev (Statistical standard deviation)

Var (Statistical variance)

Aggregates are usually performed along relationships. Create an aggregate expression by using one of the functions listed above and a child table column as detailed in PARENT/CHILD RELATION REFERENCING above. For example:

Avg(Child.Price)
Avg(Child(Orders2Details).Price)

An aggregate can also be performed on a single table. For example, to create a summary of figures in a column named “Price”:

Sum(Price)

Note: If you use a single table to create an aggregate, there would be no group-by functionality. Instead, all rows would display the same value in ...