Domain Aggregate Functions [Access 2003 VBA Language Reference]

Aggregate functions provide statistical information about sets of records (a domain). For example, you can use an aggregate function to count the number of records in a particular set of records or to determine the average of values in a particular field.

The two types of aggregate functions, domain aggregate functions and SQL aggregate functions, provide similar functionality but are used in different situations. The SQL aggregate functions can be included in the syntax of an SQL statement but can't be called directly from Visual Basic. Conversely, the domain aggregate functions can be called directly from Visual Basic code. They can also be included in an SQL statement, but an SQL aggregate function is generally more efficient.

If you are performing statistical calculations from within code, you must use the domain aggregate functions. You can also use the domain aggregate functions to specify criteria, update values, or create calculated fields in a query expression. You can use either the SQL aggregate or domain aggregate functions in a calculated control on a form or report.

The domain aggregate functions include:

DAvg Function

DCount Function

DLookup Function

DFirst, DLast Functions

DMin, DMax Functions

DStDev, DStDevP Functions

DSum Function

DVar, DVarP Functions