History
This is from the old Postgres Schema and idea of History, it is kept here whilst it is in TODO.
| history | DATA TYPE |
|---|---|
| id | INTEGER |
| record_id | INTEGER |
| change_time | STRING |
| old_quantity | FLOAT |
| new_quantity | FLOAT |
History is a table that automatically logs the change of a record's quantity, to use the 'sum' table.