Re: Orafce concat operator
От | Yeb Havinga |
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Тема | Re: Orafce concat operator |
Дата | |
Msg-id | 4B72D74B.7040903@gmail.com обсуждение исходный текст |
Ответ на | Re: Orafce concat operator (Pavel Stehule <pavel.stehule@gmail.com>) |
Ответы |
Re: Orafce concat operator
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Список | pgsql-general |
Pavel Stehule wrote: >> What about adding something like operator ||| in the orafce package for >> concat? >> > > no, it could be confusing and it isn't enough, because it isn't only > || or concat problem. On Oracle empty string is equal to NULL and NULL > is equal to empty string. > > example: '' is null, length('') > > http://www.thunderguy.com/semicolon/2003/04/26/oracle-empty-string-null/ > > so we are not able emulate this behave. > Hi Pavel, Thanks for your quick reply. What you say is entirely true, however I'm not sure if you completely understood my question, so please do not be offended if I try to elaborate it a bit: I did not ask for full '' = NULL emulation, only for an operator to match the concat function, so that code conversion with repetetive concats are easier (string || string || string etc) which occur frequently. Ofcourse a translator can be made that converst that to concat(string,concat(string,concat(string etc))), however that's confusing too in a different way. So imho the only problem is to think of an operator that somehow resembles || so the programmer recognizes a concat, but also adds something so the programmer recognizes: not strict. What about ||+ ? And then, at the conversion of e.g. (string || string || string) IS NULL, confusion arises, but this is not due to the concat, but more to the IS NULL clause together with the strange '' = null, and that must be handled otherwise. So the operator would speed up part of the code conversion. regards, Yeb Havinga
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