Will Lion install MySQL with it? I had MAMP running on my laptop. I use MySQL a lot. I kinda messed with the user file permission and I fixed it , in that process I changed some password in MySQL config files. So now SQL does not work even though MAMP runs perfectly.

I was planing on installing OS X Lion. I am wondering if upgrading to Lion will install MySQL and all its packages? Will it fix the problem? Or should I have to reinstall MySQL even after I upgrade?
No, I don't believe Lion comes with any sort of SQL server pre-installed.