Database creation is described in the MySQL database configuration documentation.
Database population is discussed in the installation documentation.
If you are installing DLXS for the first time, database upgrading is not an issue.
If you have a Release "N" DLXS installation, an upgrade utility called upgrade_N_N+1 in $DLXSROOT/bin/db can be used to update your version "N" database to version "N+1". See documentation on database upgrading for complete instructions.
Be aware of the following:
Therefore, if you have version 12 of DLXS and have installed version 13 of DLXS, you will need to get a database version 6 set up to use with your DLXS version 13 installation.