Alternative Text Literals
New IBProvider 5.31.1.43971 has added the support of UTF16 symbols for alternative text literals. It means that provider will be correctly processing the following query:
select _win1251 q’?мама, мама, что я буду делать??’ from rdb$database;
I hope that Firebird will be able to process this query in the near future.
Note that, you should use UTF8 connection charset for executing the such queries.