last

Details: Last Updated on Friday, 18 January 2013 09:58

syntax

last(a)
last(a, partioning)

definition

last(a) results in a parameter with the last of the non null values of attribute a.
last(a, partioning) results in an attribute with the last of the non null values of attribute a, grouped by the partitiong attribute. The domain unit of the resulting attribute is the values unit of the partioning attribute.

The values unit of the resulting data item should match with regard to value type and metric with the values unit of attribute a.

applies to

Attribute a with value types:

groups: Numeric, Point
string
bool

conditions

Attributes a and partioning need to match with regard to their domain unit.

since version

5.15

example

1. parameter<uint32> lastNrInh:
      expr = "last(City/NrInhabitants)"; result = 175
2. parameter<string> lastCityName:
      expr = "last(City/CityName)";      result = ‘Haarlem’  
3. parameter<bool>   lastIsCapital:
      expr = "last(City/IsCapital)";     result = False
4. attribute<uint32> lastNrInhRegion    (RegionDomain):
      expr = "last(City/NrInhabitants, City/RegionNr)"; 
5. attribute<string> lastCityNameRegion (RegionDomain):
      expr = "last(City/CityName,      City/RegionNr)"; 
6. attribute<bool>   lastIsCapital      (RegionDomain):
      expr = "last(City/IsCapital,     City/RegionNr)";

City/NrInhabitants	City/CityName	IsCapital	City/RegionNr
550	Amsterdam	True	0
525	Rotterdam	False	1
300	Utrecht	False	2
500	DenHaag	False	1
200	Eindhoven	False	3
175	Haarlem	False	null
null	null	False	3

Table CityDomain, nr of rows = 7

lastNrInhRegion	lastCityNameRegion	lastIsCapitalRegion
550	Amsterdam	True
500	DenHaag	False
300	Utrecht	False
200	Eindhoven	False
null	null	False

Table RegionDomain, nr of rows = 5