Clearing

Clearing is more than just checking an account balance. It is another way of grouping
existing split bookings of different transactions. This is very similar to clear
invoices against payments; which would be covered by this more general approach as well.

In gnucash two or more splits are grouped to one transaction.
That transaction has a timestamp when it has happened.
Clearing means to group splits of different transactions into a "clearing group".
This "clearing group" has no timestamp.
It just helps to find splits which are not yet "cleared".

To achieve this, each split needs one additional column:

ALTER TABLE split ADD ( clearing_group CHAR ( 32 )); // can be null

Clearing goes as:

1. Find the first split booking which should be part of the clearing group

2. use right mouse key (or button or menu) to remember this split-guid
   If "split.clearinggroup" is null then create a new GUID and update this field
   UPDATE split SET clearinggroup = $new_guid
   If its not null, then just remember (copy) that value

3. Find the next split booking which should be part of the clearing group

4. use right mouse key (or button or menu) to add this split booking to the group
   UPDATE split SET clearinggroup = $rememberedguid

5. Continue with steps 3 and 4 until the clearing group is complete

Now we need a register like the journal with all clearing groups (shortcut directly
from a split booking out of any other register). Could be sorted by the transaction
dates coming from the grouped split bookings.

A split booking is cleared (could be shown by a new column having a green checkmark)
when the amounts for debit and credit match within the group.

To show that a split booking belongs to a clearing group but is not yet cleared can
be displayed by a yellow exclamation mark (instead of the green checkmark).

To show that a split booking does not even belong to a clearing group can
be displayed by just a space.

Additional functionality could be to configure that all splits with an account of
type (Forderungen und Verbindlichkeiten) receivables or payables HAVE TO be cleared.