Hello,
You are getting this error because you created your FULLTEXT index only on one column (prod_desc). If you want to search prod_name and prod_desc in one shot, you have to create a FULLTEXT index on (prod_name, prod_desc). According to the
MySQL manual, you can use MATCH on any column included in a FULLTEXT index, which means that in your case, if you create just a FULLTEXT index on (prod_name, prod_desc), you will be able to use MATCH(prod_name, prod_desc), MATCH(prod_name) and MATCH(prod_desc).
Regards,
RBARAER