Sql LIKE how to do case and character insensitive?

Question

MySQL

It took a LIKE query, taking into account only the letters of the Latin and Russian alphabet, without taking into account all other characters and without regard to case.
Prompt an example, or in what documentation to look.
And he should work as quickly as possible, because. There are more than 1 million entries in the table.

Answer 1

Caseless:
The full version is something like this: (if you need spaces, add \s )
where lover(column_name) regexp '^[a-zа-яё]+$';