Reply to Djing in a Club

Hello Djs,

I'm relatively new to djing, only been doing it for less than a year and I had a question about how do djs mix their
songs in a club. I mostly mix Electro Dance music so I know about beat-matching and all the basics, but my question
was just exactly how you would mix your songs in a club? What I've been noticing is when I go to a club is djs dont
play the songs for too long, they try to keep the excitement up and not have the crowd waiting for too long, but i
need to get more info. For example, do they have their own edits of songs to make them easier to mix (I saw a dj ata club mixing the drum beat of The Motto then Drake started rapping, but the original version starts with drake
rapping on the first beat)? How long should a song be played? How to know which songs to play(mixing in key)? How to time your songs right for the whole evening ? Things like that.. Any advice and tips from all club Djs out there would be helpful and much appreciated.

Thanks.