id summary reporter owner description type status component version severity resolution keywords cc stage has_patch needs_docs needs_tests needs_better_patch easy ui_ux 25772 ArrayField: incorrent len lookup on empty arrays mrAdm Tim Graham "Models: {{{ NullableIntegerArrayModel.objects.create(field=[]) NullableIntegerArrayModel.objects.create(field=[1]) NullableIntegerArrayModel.objects.create(field=[2, 3]) NullableIntegerArrayModel.objects.create(field=[20, 30, 40]) }}} Queries: {{{ NullableIntegerArrayModel.objects.filter(field__len=0) # return: empty queryset NullableIntegerArrayModel.objects.filter(field__len__lt=2) # return only one model (field=[1]) }}} Reason: PostgreSQL function array_length(ARRAY[]::int4[], 1) return null if array empty. The solution is to use a function PostgreSQL: COALESCE (). {{{ SELECT * FROM ... WHERE COALESCE(array_length(""field"", 1), 0)=0 }}}" Bug closed contrib.postgres 1.8 Normal fixed Accepted 1 0 0 0 0 0