select count(*) as cnt from wiz_product a inner join wiz_cprelation b on a.prdcode = b.prdcode where auction = 'N' and showset = 'Y' and a.common_member = 'N' and c.sales_grade='22'

1054 : Unknown column 'c.sales_grade' in 'where clause'

error file : /sub/product_search.php