I think he meant that random people can't come onto schools with guns but he said employees of the school should have access to them. I don't see the contradiction here.
Riiiiiiiiiiiiight, because the question of "should random people come into schools with guns" is a deeply divided issue that the country and its political parties are split on. A question on which after careful consideration of the pros and cons Rump courageously takes a stand.
As for random people coming onto schools --- that's just perverted.
Had Trump been asked the same question you posed, his answer would have been no, just like any thinking adult's answer would have been.
His stand is, not everybody should bring guns into schools, but trained teachers, having a gun, and the ability to protect our children is a good idea. He's correct. Gun free zones are targets. Our children are targets. Cowering in a closet isn't an effective deterrent.
Trump 2016, because our kids should be protected.
In other words "Yes", and by 'yes' I mean "No". And vice versa.
As the topic says, this ain't rocket surgery to understand. Until Self-Delusion steps in.
Ignorance is Strength.