No, there isn't a national database that is automagically searched when an officer runs your license. In some states the license is tied to the CPL so it comes up and in others it is not. Michigan used to have it come up but the law changed and the officer must do a specific search of the CPL database rather than a general search.
It is important that people understand that the "duty to inform" differs from state to state. In some states, Michigan is one, you are _required_ to immediately inform if you are detained, (a traffic stop counts), if you are in possession of your concealed pistol. In other states you do not.
It's also important to understand that in some states a "no firearms" sign carries the weight of law while in others they do not though if you are caught you can be charged with trespass if you do not leave immediately when asked.
It's also important to know that some jurisdictions have "silly" rules that can catch you out. My "favorite" because I have to pass through several times a year is Cook County, (Chicago), which has banned laser sighting devices and if found with one the pistol will be confiscated. It's bothersome because my favorite CP came with a laser built into the grip. I never use it and it is always switched off. It's bothersome because I have to remember to switch out with another pistol when I take that trip.
There is no doubt in my mind that handgunlaw.us is the best source of up to date information regarding any state's law, requirements and "silly" rules. Simply type:-
http://www.handgunlaw.us/states/STATEYOUAREVISITING.pdf
Simply replace STATEYOUAREVISITING with the full name of the state or just type:-
http://www.handgunlaw.us
Which will give you a clickable map.
No, I am not affiliated with handgunlaw.us but I do like to make sure that idiot states who disregard the constitution in order to subjugate citizens don't get a free shot at people innocently passing through.