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syntax

definition

lookup(index number,values) or values[index number] results in a data item with the values of attribute values for the domain of data item index number. The index number attribute defines which values are looked up.

description

The index number towards the domain unit of attribute values can be derived from any foreign key attribute with the rlookup function. The rjoin function can be used to relate on key attributes, without using index numbers.

since version

5.15

example

The following two examples are synonyms:
attribute<degrees> LTemp (City) := lookup(City/Region_rel, Region/Temp);
attribute<degrees> LTemp (City) := Region/Temp[City/Region_rel];
City/Region_rel   LTemp
0 12
1 11
2 null
1 11
3 14
null null
3 14
domain City, nr of rows = 7

Region/Temp
12
11
null
14
13
domain Region, nr of rows = 5

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