Thank you Stanley.

I think it's better ti remove a word and you can said as this: He knows nothing about his job.

In regular spoken English you would say, "All he (ever) does is bitch about his job." While the two formulations are grammatically correct it sounds like you are translating an idiomatic expression from your native language. Actually, your exact formulations exist in other languages, but in spoken English we would say it as above.

Thank you for answering. How do you say something like that usually?

Yes, they mean the same thing, but these constructions are used very rarely.