ordering-functions less than or left side has null values


  • lt_or_lhs_null(a,b)


lt_or_lhs_null(a, b) results in a boolean data-item indicating if the values of data item a are less than the corresponding values of data item b or if the values of data item a are null.


The comparison with missing values in data item a results in the value True (except for null values in data item b).

applies to

Data items with Numeric, string or bool value-type


  1. Domain of the arguments must match or be void (literals or parameters can be compared to data items of any domain).
  2. Arguments must have matching:


attribute<bool> AltB (CDomain) := lt_or_lhs_null(A, B);
A B AltB
0 0 False
1 2 True
2.5 2.5 False
-100 100 True
999 -999 False
null 0 True
null null False
0 null False
null 100 True
100 null False

CDomain, nr of rows = 10

see also