how to check database size in mysql

check_mysql_db_size.sql

SELECT 
    table_schema 'Database Name',
    SUM(data_length + index_length) 'Size in Bytes',
    ROUND(SUM(data_length + index_length) / 1024 / 1024, 2) 'Size in MiB'
FROM information_schema.tables 
GROUP BY table_schema;

select count(user), user,
host,
db
from information_schema.processlist group by user ;