Adding a linker to library in makefile

Hi. I added #include<mysql/mysql.h> to printdlg.cxx because I want it to connect to a database I've 
created. when I build the program it gives an error: undefined reference to 'mysql_init()'. I 
researched and the solution says put a linker 'mysql_config --cflags --libs' when compiling. Where 
do I put this linker in the makefiles? I'm still new to LibreOffice hacking. I have an application 
and I want to connect it to LibreOffice to determine how many pages to be printed to compare it to 
the user's remaining credit. if the credit is less than the number of pages then the application 
will cancel the printing. I already got the canceling  part. It's the comparing part I don't get 
because of the error: undefined reference to 'mysql_init()'. Hope you would help me out with this. 
Thanks