select @@convert_character_set;
@@convert_character_set

select @@global.convert_character_set;
@@global.convert_character_set

show variables like "%convert_character_set%";
Variable_name	Value
convert_character_set	
SET CHARACTER SET cp1251_koi8;
select @@convert_character_set;
@@convert_character_set
cp1251_koi8
SET CHARACTER SET DEFAULT;
select @@convert_character_set;
@@convert_character_set