How to Insert a Field With a Constant Into a Union Query in Access – This is a place for the community to provide tips and advice on How to Insert a Field With a Constant Into a Union Query in Access. This topic was created by Martin Cahnbley and the tips are provided by the community. The tips you add here can be your own or referred from another site. The best tips are then ranked at the top when up-voted by members of the community.