2008/12/10 Tom Lane <[EMAIL PROTECTED]>: > "Pavel Stehule" <[EMAIL PROTECTED]> writes: >> look again >> select c as foo from tab ... >> select fce(c as foo) from tab ... > >> when you use AS as param names specification, you change meaning of >> some construct via used context? > > Uh, what's your point? AS changes the meaning too. For example in > > select foo, bar from (select c as foo, d as bar from ...) ss; > > we are using AS to specify the names seen by the outer select. > This seems to me to be quite a close parallel to attaching names > to function parameters.
no, no - you use AS for an change of some property of set c column values - label. Isn't important if this is select, subselect. label is metadata - it's related to data. This is using of AS. Maybe it's different for me, because I am not native speaker, so I feeling SQL more like artifical language than you. For you using AS is more less formal - it's your natural language. So I am filling some border between data names (labels) and parameter names. next argument - if we accept AS for param names, then we introduce nonconsistent behave with SQL/XML functions. select xmlforest(c1, c2 as foo, c3) -- there foo isn't doesn't mean "use it as param foo", so from this view is using AS very dificult accaptable too. regards Pavel Stehule > > regards, tom lane > -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
