Are you trying to compile 64 bits or 32 ?
Your problem related to that, all you need to do is select the correct mysql version depending on what bits you are trying to compile.
easiest way will be to go here.
https://trinitycore.atlassian.net/wiki/display/tc/Windows+Requirements
STEP 9
- These files are shipped with MySQL Server but to make it easier we packed the libs and include files for both 32 bits and 64 bits.
Click on download link.
Place it somewhere you know where (lol)
Now open cMake place a tick on checkbox where it says advanced and grouped , it's in line with bar named search.
Now expand the MYSQL group.
and change the last 2 entries.
MSYQL_INCLUDE_DIR - must be a folder named include (you can found it your folder that you downloaded)
MYSQL_LIBRARY - must be a .lib file (can be found in your folder you downloaded)
Just don't forget if you downloaded all software for 32 bits it's doesn't matter if your OS is 64. just select 32 bit mysql folder in MYSQL_LIBRARY.
And after compile just move a .lib files from this folder to your's release folder.(like in normal way)
If you have any problems, post them here.