I have tried every dog food on the market but my 8 month old daschund is very picky' .I do not want her to have human food but I am getting desperate.help

Don't be too fussy.
Pick a food and stick with it. If you keep changing foods all the time she is going to learn that if she doesn't eat her dinner then she gets something better later.

I went through this problem with one of mine... he flat out refused to eat for quite a few days. I did what you did and bought all different foods, it made no difference.
In the end I just bought a canned food and mixed dry through it. I would put his bowl down and leave it for 15 minutes. Anything that didn't get eaten in that time was picked up and thrown away.
The next night I would do the same, 15 minutes then thrown away.
He eventually learnt that if he didn't eat it he wasn't going to get anything else, he now eats his dinner ever night with no problem.