set names utf8;
create table t1 (
a int,
b varchar(100) as (if(a,collation('й'),hex('ю')))
) character set koi8r;
insert t1 (a) values (0),(1);
select * from t1;
a	b
0	C0
1	koi8r_general_ci
set names latin1;
select * from t1;
a	b
0	C0
1	koi8r_general_ci
flush tables;
select * from t1;
a	b
0	C0
1	koi8r_general_ci
set names koi8r;
select * from t1;
a	b
0	C0
1	koi8r_general_ci
flush tables;
select * from t1;
a	b
0	C0
1	koi8r_general_ci
drop table t1;