How to make PostgreSQL not distinguish between the letters "E" and "Yo"?

Question

PostgreSQL

It is necessary that the type query returns (including) records where Well, and vice versa. I remember that in MySQL this was possible.
select * from tbl where surname = 'фёдоров';
surname = 'федоров'.

Answer 1

Solved such a problem. Came to what to do through the regular season.
If the query string contains the letter "e", then all occurrences are replaced by [e|e]
$q = str_replace('e', '[e|e]', $q);
and in sql already comes with

select *
from tbl
WHERE tbl.name SIMILAR TO '%ж[е|ё]лтый%'

Answer 2

The solution could be this:

select * from tbl where replace(surname, 'ё', 'е') = '{$surname}';

Answer 3

It is probably still possible to exclude this notorious letter e in the database . In Mysql, this query will replace all letters, if it fits, then it will be possible to avoid problems in the future. They change something in the code, dig a hole for themselves.
UPDATE table SET field = REPLACE(field, 'ё', 'е');