collect_attr_by_org_rel

relational-functions collect_attr_by_org_rel

syntax

• collect_attr_by_org_rel(tree_item, selection domain unit, org_rel)

definition

collect_attr_by_cond(tree_item, selection domain unit, org_rel) results in a new container with all subitems from the src_tree_item argument with the same domain unit as the values-unit of the org_rel argument. The org_rel attribute is used in lookup expressions to select a set of elements of the original domain, this set is defined by the second argument: selection domain unit. This selection domain unit becomes the domain unit of the collected attributes.

The resulting attributes have the same values units and composition types as the source attributes, expressions are made with the lookup function for each new attribute. This works similar to the select_afew function, with as difference that the collect_attr_by_org_rel does not create a new domain unit.

Between versions 8.5.2 and 8.7.2 the name relate_attr was used for the collect_attr_by_org_rel function.

applies to

• tree_item can by any tree-item, but usually a unit or container
• domain unit a unit with value-type of the group CanbeDomainUnit
• org_rel a relation from the domain unit argument toward the domain unit of the attributes to be collect_attr_by_org_rel.

since version

8.8.0

example

unit<uint32> City: StorageName = "city.csv", StorageType = "gdal.vect", StoragReadOnly = "True"
{
   attribute<string> name
   attribute<uint32> RegionCode;
}

unit<uint32> ZHCities := select_with_attr_by_org_rel(City, City/RegionCode == 200);

container attributes_ZHCities := collect_attr_by_org_rel(City, ZHCities, ZHCities/org_rel);

domain City, nr of rows = 7

domain ZHCities, nr of rows = 2

The subitems: name and regionCode are generated by the configured collect_attr_by_org_rel function.

see also

• collect_attr_by_cond
• select_with_attr_by_org_rel