Min

aggregation-functions min(imum)

syntax

  • min(a)
  • min(a, relation)

definition

  • min(a) results in a parameter with the minimum of the non null values of attribute a.
  • min(a, relation) results in an attribute with the minimum of the non null values of attribute a, grouped by relation. The domain-unit of the resulting attribute is the values-unit of the relation.

description

The min function is not defined for boolean data-item, use the any function instead.

If there are no values to be aggregated for a group, the resulting value will be the maximum value for the value-type of attribute a (in the example: 4294967294, the maximum value for the value type: uint32).

applies to

  • attribute a with Numeric, Point or string value type
  • relation with value ype of the group CanBeDomainUnit

conditions

  1. The values unit of the resulting data item should match with regard to value ype and metric with the values unit of attribute a.
  2. The domain of argument a and relation must match.

example

parameter<uint32> minNrInh := min(City/NrInhabitants); result = 175
parameter<string> minCity  := min(City/CityName);      result = ‘Amsterdam’

attribute<uint32> minNrInhRegion    (Region) := min(City/NrInhabitants, City/Region_rel);
attribute<string> minCityNameRegion (Region) := min(City/CityName, City/Region_rel);
City/NrInhabitants City/CityName City/Region_rel
550 Amsterdam 0
525 Rotterdam 1
300 Utrecht 2
500 DenHaag 1
200 Eindhoven 3
175 Haarlem null
null null 3

domain City, nr of rows = 7

minNrInhRegion minCityNameRegion
550 Amsterdam
500 DenHaag
300 Utrecht
200 Eindhoven
4294967294 ÿÿÿÿ1

domain Region, nr of rows = 5

1) ÿÿÿÿ represents the max value for strings

see also