Count - ObjectVision/GeoDMS GitHub Wiki

Aggregation functions count

• count(a)
• count(a, relation)

• count(a) results in an uint32 parameter with the number of non null values of attribute a.
• count(a, relation) results in a an uint32 attribute with the number of non null values of attribute a, grouped by relation. The domain unit of the resulting attribute is the values unit of the relation.

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

The domain unit of arguments a and relation must match.

1. parameter<uint32> countNrInh                := count(City/NrInhabitants); result = 6
2. attribute<uint32> countNrInhRegion (Region) := count(City/NrInhabitants, City/Region_rel);

domain City, nr of rows = 7

domain Region, nr of rows = 5

• pcount