Re: create function problem

"Thomas Leung" <thomasleung@hotmail.com> writes:
>     str := to_char($1, "YYYY");

> ERROR:  Attribute "YYYY" not found

Double and single quotes are not interchangeable.  Here you have written
an identifier, not a string literal.  You'll need
     str := to_char($1, ''YYYY'');
or
     str := to_char($1, \'YYYY\');
according to taste.

            regards, tom lane