Libreoffice CSVTODO Database
LibreOffice provides a versatile developing tool and graphical interface for databases.
BASE, the name of the application contained in the LibreOffice office suite, supports CSV formatted files as database tables. It's therefore relatively straightforward to connect the CSVTODO task list to an existing database, as shown in the video below.
The TODO list appears as a virtual table in the database and it can be easily included in a spreadsheet with a simple query. The data sources browser (CtrlShiftF4) shows exclusively registered databases, and when visible it locks CSV tables in read-only mode.
When an external program (in this case CSVTODO) modifies the CSV file, the result from a query can be updated by pressing Refresh Range from the Data drop-down menu.