On 14 March 2015 at 09:17, David G. Johnston <david.g.johnston@gmail.com> wrote: > On Saturday, March 14, 2015, Jason Dusek <jason.dusek@gmail.com> wrote: >> It honestly seems far more reasonable to me that %s and %I should do >> the exact same thing with regclass. My reasoning is as follows: >> >> ‘%I’ formats a something such that it is a valid identifier, >> >> regclass is already a valid identifier, >> >> therefore, do nothing. >> >> Another line of reasoning: >> >> If you format with ‘%s’ you are saying: I don’t care whether it’s a >> valid identifier or literal or whatever, just put the string there, >> >> but when we sub a regclass into a string, we want it to be a valid >> identifier, >> >> therefore we should write ‘%I’ when subbing it, so as not to confuse >> our readers, >> >> therefore ‘%I’ should do nothing. >> > > I agree with the theory but adding type specific logic to format is going to > be difficult. The first thing the system does is convert all of the inputs > to text. Inside format() everything is text and so it has no way to know > that the type was regclass and should not be quoted again.
Could it work to add type-specific logic for the cast from `regclass` to `name`? It would be nice to have something formulaic: always format identifiers with `%I`, always cast to `name` before formatting.
I don't think, so it can help - first, it is workaround and it doesn't help for somebody who doesn't read a documentation. Same effect you can get if you write "doesn't use %I for regclass, regtype types", although this sentence is strange. I agree with you so it is bug or minimally not user friendly design.
A some good solution should be safe function quote_identif, that protect us against double quoting. This logic should be elsewhere than inside "format" function. I am thinking so we can do it. It breaks nothing. Implementation should not be too much complex, because "new" function quote_identif can do nothing for safe types, so it can take string as input parameter and typid as second parameter.