My customer model has a `first_name` and `last_name` field. I can query the model with the following code:

```
Customer.where(first_name: "John").where(last_name "Doe")

```

However, I want to query the model like this:

```
Customer.where(full_name: "John Doe")

```

But I do not have a full\_name column. How can I accomplish this without creating a `full_name` field?