MySQL finds records containing non-ASCII character values

SELECT * FROM my_table WHERE NOT HEX(my_column) REGEXP '^([0-7][0-9A-F])*$';
 
-- 相反的，找出只包含ASCII字符的记录
 
SELECT * FROM my_table WHERE HEX(my_column) REGEXP '^([0-7][0-9A-F])*$';