union_unit - ObjectVision/GeoDMS GitHub Wiki
Relational functions union_unit
- union_unit(a, b, ... , n)
union_unit(a, b, ... , n) results in a uint32 domain unit, based on the domain units: a, b, .., n.
The number of elements of the new domain unit is the sum of the number of elements of the domain units: a, b, .., n.
Use void as domain unit for parameters that need to be added to the resulting unit, see example 2.
Use the union_data function to union data items for new domain units.
The union_unit function results in a uint32 domain unit. Use a union_unit_uint8_16_32_64 function to configure a domain of another value type.
Units a, b, .., n with value types from the group CanBeDomainUnit
1: union two domain units
unit<uint32> HollandCity := union_unit(NHCity, ZHCity); Result = domain unit with 8 rows
unit<uint32> NHCity: nrofrows = 3;
unit<uint32> ZHCity: nrofrows = 5;
2: union a domain unit and a void domain (to be able to use union_data to union an attribute and a parameter)
unit<uint32> src: nrofrows = 2
{
attribute<.> id := id(.);
}
parameter<uint32> id_param := 10;
unit<uint32> src_param := union_unit(src, void)
{
attribute<uint32> id := union_data(., src/id, id_param);
}