I just downloaded Liquibase 3.6.2, added the MariaDB driver and ran this command:

```
liquibase --url jdbc:mariadb://localhost:3306/db --changeLogFile changeLogFile.txt --username XXX --password xxx --diffTypes="data" generateChangeLog
Starting Liquibase at Mon, 17 Dec 2018 16:15:16 CET (version 3.6.2 built at 2018-07-03 11:28:09)
Liquibase command 'generateChangeLog' was executed successfully.

```

After that the file changeLogFile.txt exists in the current directory but is empty. The database however contained 11 empty tables. I would have expected some XML frame plus create table statements.

What should I do differently?