The most common mistake people make when they seek happiness (at work or in life) is that they focus on making themselves happy here and now.
This almost always fails because it becomes a meaningless, shallow pursuit of their own short-term pleasure.
True happiness on the other hand, comes from doing things to make many people (including yourself) happier in the long term.
This is illustrated by one of the most consistent findings in positive psychology, namely that if you want to be happier yourself, the best way is to make someone else happier. Not as a quid-pro-quo, but from a realization that we are social beings and that your happiness cannot be meaningfully extracted from the happiness of everyone around you.
And that goes in the workplace as well. If you want to be happy at work, focus more on making others (co-workers, customers, employees, vendors, random passers-by) happy by doing awesome work and by being an awesome person. If your workplace doesn’t let you do that, you will never be happy there.