So then the steps are:
1. Download the database as a temp-file
2. Rename database on the server-side to ensure no other app can use it.
3. Run app
4. On/before exit app upload new database-file.
5. on upload complete delete old database server-side
6. delete temp-file
depends on the degree of freedom you need/want. My personal preference would be to go the other way around. eg
1. Download the database as a temp-file
2. Run app
3. On/before exit app upload new database-file.
4. upload the changed database
5. Rename the old database on the server-side to ensure no data loss.
6. make sure that only the new database file can be downloaded
7. keep the temp database file and only re download it if the data need updating.
when you are at home you download all the old files and merge them in one to make sure that no data is lost replacing or not the existing database file on the server if needed.
In any case since this is going to be a single user application ee no way to have two version of the file edited in parallel by multiple downloads I guess your version looks safer but it does not cover in between updates or long execution/crashes etc.