id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
5929	Allow Fields to use multiple db columns (complex datatypes)	Daniel Poelzleithner	nobody	"
Currently it seems that it is not possible to have complex db filds. For example:
[https://dev.leipzig.freifunk.net/trac/browser/ffsomething/branches/generic/apps/management/models.py Implementation of a IP model] which actually should be a field type not a model. The implementation is not clean, because foreign key lookups for example do not work. The model maps for example:
{{{
NetworkAddress.objects.filter(ip__in=""192.168.0.10/16"")
}}} 
into a complex query for a ip resisting in a network range.

Due the fact that model fields can only map to one db column, many complex data types can't be implemented. For example a ipv6 ip address which is a 128 bit value can't be handled by most db implementations of integer fields, so it has to be expanded to multiple columns plus a additional netmask column. Using varchar doesn't work because there is no way to search for network ranges or IPs in ranges, etc... 
I think a field should be able to implement lookup mappings which can be overridden to implement complex datatypes as well as use multiple db fields.
"		new	Database layer (models, ORM)	other branch			qs-rf		Unreviewed	0	0	0	0