License in upgrading developer edition SonarQube

I have a developer edition SonarQube, the version of which is 6.7.1(LTS). I want to upgrade it to 7.9.2(LTS).

I have two concerns about license.

a. Is the original license key still valid after upgrading to 7.9.2(LTS)?

b. The second concern is a little bit technical.
As the database of my original SonarQube 6.7.1 is MySQL which is not supported in 7.9.2 any more, so I need to upgrade several times until I can reach 7.9.2.

Here is the upgrade path I am planning to use:
SonarQube 6.7.1(MySQL) ----> SonarQube 6.7.7(MySQL) ----> SonarQube 6.7.7(PostgreSQL) ----> SonarQube 7.9.2(PostgreSQL)

My concern is: do I need a license key for the SonarQube 6.7.7(MySQL) and SonarQube 6.7.7(PostgreSQL) when I do the upgrade?


The upgrade path used in the practical final upgrade is:
SonarQube 6.7.1(MySQL) ----> SonarQube 6.7.1(PostgreSQL) ----> SonarQube 7.9.2(PostgreSQL).

The new license should be applied after upgrading to SonarQube 7.9.2(PostgreSQL) and no license is needed in the process of doing upgrade.