Learning
Community
Open Exchange
Global Masters
InterSystems IRIS Data Platform 2019.3 / Application Development / InterSystems MDX Reference / MDX Functions / AGGREGATE
Previous section   Next section

AGGREGATE

Returns the aggregate value for a given measure (or of the current measure), across all elements of a set, according to the aggregation logic of the measure.

Returned Type

This function returns a number.

Syntax and Details

AGGREGATE(set_expression, optional_numeric_expression)
Where:
  • set_expression is an expression that evaluates to a set, typically a set of members or tuples.
  • optional_numeric_expression is a numeric-valued expression that the function evaluates for each set element.
    Typically, this expression has the form [MEASURES].[measure_name]
    If you do not specify a numeric expression, the system uses the measure used by the current result cell. For example, this might be the measure used on the 0 axis or the measure specified in the WHERE clause, if any. If the query itself does not specify a measure, the system instead uses %COUNT, which counts records in the fact table.
The function evaluates the numeric value for each element of the set and returns the aggregate value of those values.

Example

First, the following query shows values of three measures for the members of the aged.decade level:
SELECT {MEASURES.[%COUNT],MEASURES.[encounter count],MEASURES.[avg test score]} ON 0, 
birthd.decade.MEMBERS ON 1 FROM patients
                     Patient Count    Encounter Count     Avg Test Score
 1 1910s                         80              5,359              75.17
 2 1920s                        227             12,910              74.20
 3 1930s                        567             33,211              74.67
 4 1940s                        724             38,420              73.39
 5 1950s                      1,079             46,883              73.72
 6 1960s                      1,475             57,814              74.16
 7 1970s                      1,549             49,794              74.35
 8 1980s                      1,333             35,919              74.13
 9 1990s                      1,426             29,219              74.79
10 2000s                      1,406             20,072              74.95
11 2010s                        134              1,346              73.55
Next, the following query uses AGGREGATE to find the aggregated values for these measures, across this set of members:
SELECT {MEASURES.[%COUNT],MEASURES.[encounter count],MEASURES.[avg test score]} ON 0, 
AGGREGATE(birthd.decade.MEMBERS) ON 1 FROM patients
                     Patient Count    Encounter Count     Avg Test Score
AGGREGATE                    10,000            330,947              74.28
The following query uses the second argument of the AGGREGATE function:
SELECT AGGREGATE(birthd.decade.MEMBERS, MEASURES.[%COUNT]) ON 0 FROM patients
                                 AGGREGATE
                                     10,000
For additional, similar examples, see AVG. Also see examples in “Defining Calculated Members” in Defining Models for InterSystems Business Intelligence.

See Also

Previous section   Next section