& their sturcture are given below:

1. Structure of Employees table 

```
EmployeeID  LastName    FirstName   BirthDate   Photo   Notes

```
2. Structure of Customers table 

```
CustomerID  CustomerName    ContactName Address City    PostalCode  Country

```

Question:
lastname column is not present in customers table then also why the below query is giving output.

```
select *
from employees
where lastname in (select lastname from customers)

```

can any one please explain this?