I am perplexed a bit. I execute a simple `SELECT` query to MySQL DB for a record, which does not exist and get a HTTP 200 response with null for every element. Query is executed via RESTful API, which is still being developed by me. Maybe I missed something, for example, a definition of a response code?

DB

[![enter image description here](https://i.stack.imgur.com/AgIWE.png)](https://i.stack.imgur.com/AgIWE.png)

Query

`SELECT *
FROM csv_data.data
WHERE id = 20`

Response (HTTP 200 OK)

`{
 "id": null,
 "purchase": null,
 "price": null,
 "date": null,
 "notes": null
}`

API RAML

`/{purchaseId}:
 uriParameters:
 purchaseId:
 type: string
 description: Id of a purchase
 required: true
 example: "4"
 get:
 displayName: Get a single purchase
 description: Gets a single record of purchase
 responses:
 200:
 description: Status 200
 body:
 application/json:
 type: Purchase
 example: !include examples/get_purchase_example.json
 400:
 description: Status 400
 body:
 application/json:
 type: Error`

DB schema

[![enter image description here](https://i.stack.imgur.com/1mCvZ.png)](https://i.stack.imgur.com/1mCvZ.png)

Shouldn't I get HTTP code 404 or 400?