When running:
```
DELETE FROM customers WHERE id=1004;
```
I get back:
```
ERROR 1451 (23000): Cannot delete or update a parent row: a foreign key constraint fails (`inventory`.`addresses`, CONSTRAINT `addresses_ibfk_1` FOREIGN KEY (`customer_id`) REFERENCES `customers` (`id`))
```
So I added some instructions on deleting this entry first before continuing.
