Join_equal_values

---

title: Join equal values permalink: /Join_equal_values/

Relational functions join_equal_values

syntax

• join_equal_values(first_rel, second_rel)

definition

join_equal_values(first_rel, second_rel) results in a new uint32 domain unit with entries for each combinations of all equal values of first_rel and second_rel. The functions results in three subitems:

• nr_1_rel: the index numbers of the combination of equal values in the domain unit of the first argument
• nr_2_rel: the index numbers of the combination of equal values in the domain unit of the second argument
• nr_X_rel: the equal value in the combination

The explicit: join_equal_values_uint64, join_equal_values_uint32, join_equal_values_uint16 and join_equal_values_uint8 functions can be used in the same manner as the join_equal_values function, to create a new domain unit with an explicit value type.

applies to

• first_rel: a uint32 relation
• second_rel: a uint32 relation

conditions

1. The values unit of the arguments: first_rel and second_rel must match.
2. The domain of arguments: first_rel and second_rel must be zero based.

since version

7.411

example

unit RegionCity := join_equal_values(region/country_rel, city/country_rel);

nr_1_rel	nr_2_rel	nr_X_rel
0	1	0
1	1	0
2	0	1
3	0	1
4	2	2

domain CityRegionCombinations , nr of rows = 5

region/country_rel
0
0
1
1
2

domain region, nr of rows = 5

city/country_rel
1
0
2

domain city, nr of rows = 3