Add HINT for COPY TO when WHERE clause is used.
COPY TO does not support a WHERE clause, and currently fails with the error:
ERROR: WHERE clause not allowed with COPY TO
Since the intended behavior can be achieved by using
COPY (SELECT ... WHERE ...) TO, this commit adds a HINT
to the error message:
HINT: Try the COPY (SELECT ... WHERE ...) TO variant.
This makes the error more informative and helps users
quickly find the alternative usage.
Author: Atsushi Torikoshi <torikoshia@oss.nttdata.com>
Reviewed-by: Jim Jones <jim.jones@uni-muenster.de>
Discussion: https://postgr.es/m/
3520c224c5ffac0113aef84a9179f37e@oss.nttdata.com