A. "select col_name from table where col_name is not null;"过滤字段中的空值

B. "select col_name from table where col_name >=0;"过滤字段中小于0的数据

C. "select col_name from talbe where not like '%A%'"过滤字段中带有'A'的数据

D. "select distinctcol_name from table;"过滤字段中的重复数据