select_with_org_rel - ObjectVision/GeoDMS GitHub Wiki

Selection functions select_with_org_rel

• select_with_org_rel(condition)
• select_uint8_with_org_rel(condition)
• select_uint16_with_org_rel(condition)
• select_uint32_with_org_rel(condition)
• select_uint64_with_org_rel(condition)

select_with_org_rel(condition) results in a new domain unit with a relation to the entries of the domain unit of the condition, for which the values of the condition argument are true.

The resulting value type of the domain unit is derived from the domain unit of the condition argument:

• uint32 for conditions with uint32, boolean, spoint or wpoint value type
• uint8 for conditions with uint8 value type
• uint16 for conditions with uint16 value type
• uint64 for conditions with uint64, ipoint or upoint value type

Between versions 8.44 and 8.7.2 the name select_orgrel was used for the select_with_org_rel function.

The explicit select_uint8_with_org_rel, select_uint16_with_org_rel, select_uint32_with_org_rel and select_uint64_with_org_rel functions can be used in the same manner as the select_with_org_rel function, to create a new domain unit with the explicit value type.

The select_with_org_rel function generates a subitem, named org_rel. This data item contains the relation towards the domain unit of the condition argument.

The select_with_org_rel and subset functions are similar, the only difference is that the subitem generated by the subset operator is called: Nr_OrgEntity, a name that does not meet with our naming conventions.

The org_rel data item can be used in a lookup function to relate attributes to the new domain unit, see the example.

See this overview for when to choose which selection operator is feasable.

• condition must be a boolean attribute or subexpression resulting in boolean values.

8.8.0

unit<uint32> ZHCities := select_with_org_rel(City/RegionCode == 200)
{
   attribute<string> name := org_rel -> Name;
}

domain City, nr of rows = 7

domain ZHCities, nr of rows = 2

• select
• select_data