standards_conforming_strings=off confuses duckdb parser

[hlinnaka]

postgres=# set standard_conforming_strings =off;
SET
postgres=# select * from foo where t = 'foo\'bar';
WARNING:  nonstandard use of \' in a string literal
LINE 1: select * from foo where t = 'foo\'bar';
                                    ^
HINT:  Use '' to write quotes in strings, or use the escape string syntax (E'...').
WARNING:  (DuckDB) Parser Error: syntax error at or near "bar"
LINE 1: select * from foo where t = 'foo\'bar';
                                          ^
ERROR:  unrecognized node type: 1

[Reminiscent]

@wuputah @hlinnaka What do you think the best way to fix this issue?

1. support standards_conforming_strings in duckdb for compatible. -> I see tThe purpose of this guc is to be compatible with the behavior of old versions of postgres. Maybe it's not good idea to do this.
2. handle this logic in the pg_duckdb. Do some pre-process in the pg_duckdb.
3. forbid to use the duckdb when we find we use this GUC.

A general question is what is the general approach for some GUCs that may change behavior or be incompatible with duckdb, or is it handled on a case-by-case?

[JelteF]

This is now fixed by #130, I now added a test for this in #135