ADOTable.Edit修改表的问题(50分)

想用ADOTable.Edit修改表
ADOTable1.Edit;
ADOTable1.FieldByName('Quantity').AsString:=xx;
怎样才能做到SQL语句的效果啊,也就是说怎么过滤ProductName啊
update Storage set Quantity='XX' where ProductName='yy'

ADOTable1.filtered := false;
ADOTable1.filter := 'ProductName = '''+你的参数+''' ';
ADOTable1.filtered := true;
ok,下面遍历所有ADOTable1的记录，直接修改Quantiy