Re: help: now() + N is now failing!
От | Dmitry Tkach |
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Тема | Re: help: now() + N is now failing! |
Дата | |
Msg-id | 3F26C768.4040005@openratings.com обсуждение исходный текст |
Ответ на | help: now() + N is now failing! ("Mel Jamero" <mel@gmanmi.tv>) |
Ответы |
Re: help: now() + N is now failing!
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Список | pgsql-novice |
Stephan Szabo wrote: >The first doesn't, date_pli('foo', 2) that's just text->date > But you can't cast 'foo' into date, can you? I mean, there is a cast, but it will fail, right. And if you used a valid date textual representation, then, I don't see any reason why date_pli ('29/07/03', 2) should not work And, as a matter of fact, it *does*, unless you add '::text' to it (in 7.3 - 7.2 is still OK with it). > (the other >does, but it was a more rediculous example using two casts - I don't >see much stretch from allowing all casts implicitly to allowing multiple >casts really in the abstract anyway) > Well... I don't know about the 'stretch' :-) I am just trying to use the analogy with programming language (like C++, or Java) that allow function/operator overloading - they do allow single-step casts (as long as it is no ambigous), but not multiple step ... they also allow downcasting (e.g. using a superclass of the declared argument argument), even for "primitive" types actually (it will implicitly coerce a double into an int for example if you send it into a function that expects an int, even though it will complain about it first, which, BTW I believe to be inconsistent - if you can coerce a subclass into a superclass, there is not much difference in casting double into an int really)... So, I just have a little trouble understanding why postgres cannot use those same rules, and has instead to "reinvent the bycicle" and come up with some of its own... Dima
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