当然我想知道如何在发布之后立即执行此操作，当然这是在Meteor文档中建议的！

Of course I figure out how to do this right after posting, and of course it's suggested in the Meteor documentation!

当然，它是一个简单的解决方案：

And, of course, it's a simple solution:

collection.update({A: true, B: true}, {$set: {C:false}});