Re: Missing ParameterStatus for backslash_quote

Tom Lane wrote:
> Michael Paesold <mpaesold@gmx.at> writes:
>> Assuming the documentation is correct, this variable is not reported via 
>> ParameterStatus messages.
> 
> That's intentional.  There is no reason for an application to need to
> know about that variable, because there is no reason for it to change
> behavior in consequence.  Applications shouldn't be using backslash-quote,
> period -- quote-quote is always correct instead.

FWIW, I am just changing the JDBC driver to use quote-quote instead of 
backslash-quote in the cases where the driver does escaping. I think 
this should be back-patched to all supported branches.

>> This is a problem for the query parsing code inside the JDBC driver 
>> because it needs to know about the state of this variable so that 
>> parsing a query in the driver has the same result as in the backend.
> 
> I don't see that the JDBC driver needs to know about it either.
> Changing the setting only causes an error to be reported (or not) ---
> it does not affect the meaning of a string.  Also, the default setting
> won't affect JDBC because JDBC only uses client_encoding = UTF8.  AFAICS
> JDBC can assume that backslash-quote is legal and the backend will
> reject it if not.

You are absolutely right. I was fooled by, e.g. the string constant 
'C:\'. With standard_conforming_strings on, this is legal, 
backslash-quote is not considered anyways. But without standard 
conforming strings, this is illegal anyways, because it should have read 
'C:\\'.

So less work for me. :-)

Thanks, Tom.

Best Regards
Michael Paesold