confirguration in radiusd.conf

[Raymond]

Hi,   I install freeradius and change authentication typ to mysql. I did change radiusd.conf . But, it got the error message when I run /usr/local/sbin/radiusd -X.     rlm_sql (sql): Could not link driver rlm_sql_mysql: file not found rlm_sql (sql): Make sure it (and all its dependent libraries!) are in the search path of your system's ld. radiusd.conf[14]: sql: Module instantiation failed.   Does anyone know the reason of it?   Regards,   Raymond