Kevin Murphy <murphy@xxxxxxxxxxxxxxx> writes: > Substitute the following pairs of values for X and Y in the query below, > and all of them work (in PG 8.3.6, at least): > X Y > g g > i g(i) > g g(i) > g.i g(i) > create or replace function unnest(anyarray) > returns setof anyelement as $$ > select $1[X] from generate_series(array_lower($1,1),array_upper($1,1)) Y; > $$ language sql; The reason they all work is that generate_series() returns a scalar (ie, an integer). In all these cases the table alias "g" would resolve as the function's whole-tuple result, but that's just an integer. We also provide a column alias for the scalar value, which is why cases 2 and 4 work. In case 1 the alias Y is really being read as g(g), so you could also have written X as g.g if you like being pedantic. I think BTW that the unqualified reference to g will be resolved preferentially as being a column alias not a table alias, but you end up at the same result either way for a scalar function. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
