so, I hate my job, they give me many tasks (many of tasks are not on my field) with no trainings and no time, plus a salary that is not that good.

I get angry, so I talked with the boss about leaving yhe company.
Well, our discussion ended up by convincing me to stay with the double of the salary.

So, I accepted the offer.
Don't know whether it's the right decision or not..

Congrats!
I understand your doubts, for it could also mean that they paid you half of what you're worth. :)

have some interviews with other companies and see if there is something you like more. And then change the company.

My old job paid well and it was a similar situation to yours, but it wasn't worth it to me so I left. I don't regret leaving, my new job is more satisfying. If you enjoy your field, look for other jobs that allow you to practice it with fair compensation.

I hope all goes well with you in this instance. What usually happens with this is that they just use your increase in salary as justification for making you do more and more shit.

@ragnarr023 exactly, I am starting​feeling this..

I had similar issues at my old job. They gave me a 20% pay increase (my wage at the moment was ok already), and decided to stay.

I quit 6 months later. Company was still shit, despite giving me more money.

Double? I'd at least see where this goes for a few months...

I am happy for your raise, try your best, keep calm, always give deadlines you can keep even when you are not asked to give a deadline, go on holidays, don't work for the company in your freetime, overdue only if it is payed, if it was your delay or you like the project. Only start new project when the former was done, never raise your voice, raise your reputation, ask for juniors upon needed, and most importantly never forget that you are the one who makes money for the company. If they play fair, be fair and you will climb higher, if they play unfair don't afraid to quit and if in this case don't forget it is not your duty to find a good replacement for yourself. Do you consent? :)

Doubling your salary is probably a good career move! If you leave soon enough to not have gotten used to the new salary, you have quite the leverage when picking your next gig.

I mean, you could very probably find a job you'd like and also bring your new salary with you to the next place!