I've got a handheld pendant that has a cable coming out the end of it, which we connectorize. When I buy it, it is all one part number (no part number for just the cable). Another example would be a prox sensor which has a cable molded onto it.
I haven't come up with a good strategy of handling parts like this in Solidworks Electrical.
The route I've been taking is having the pendant be a component, and making up a fake cable part named "pendant cable" or something like that, so that we don't end up ordering extras.