asp.net - Couldn't do inner join in grid view -

i'm totally new asp.net. please help

i'm trying connect 2 tables using inner join. worked when query is: select orders.orderid, orders.orderdate orders inner join customers on orders.customerid=customers.customerid;

but throws error "a field or property name 'customername' not found on selected data source" when query changed to:

select orders.orderid, customers.customername, orders.orderdate orders inner join customers on orders.customerid=customers.customerid;

but when tested query, ran

note: i'm using access db sql data source , using vb asp.net

it appears customers table doesn't contain column name 'customername'. can check real please.. maybe typo?

open database using access check this.