[Mysql] Mysql command

Các lệnh mysql

1. Show current database is selected:

SELECT DATABASE() FROM DUAL;

2. Import/Export mysql

https://www.digitalocean.com/community/tutorials/how-to-import-and-export-databases-and-reset-a-root-password-in-mysql
Note:
a. Tránh lock bảng
--lock-tables=false --compact
b. Sử dụng lệnh source để xem kết quả import trên từng dòng
https://dev.mysql.com/doc/refman/5.7/en/mysql-batch-commands.html

3.  View a list of mysql users and their privileges

http://xmodulo.com/how-to-view-list-of-mysql-users-and-their-privileges.html

• To get a list of MySQL users

mysql> select user,host from mysql.user;

4. size of tables

http://stackoverflow.com/questions/9620198/how-to-get-the-sizes-of-the-tables-of-a-mysql-database

You can use this query to show the size of a table (although you need to substitute the variables first):
SELECT 
    table_name AS `Table`, 
    round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB` 
FROM information_schema.TABLES 
WHERE table_schema = "$DB_NAME"
    AND table_name = "$TABLE_NAME";

or this query to list the size of every table in every database, largest first:
SELECT 
     table_schema as `Database`, 
     table_name AS `Table`, 
     round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB` 
FROM information_schema.TABLES 
ORDER BY (data_length + index_length) DESC;