Survey database design: associate an answer to a user
I'm doing the conceptual model for a survey database.
The goal is store the answers given by users (it's going to be an Android app).
I have three entities: user, question and option.
A question will have one or more options (for example: How many employees do you have? 1-40, 40-1000, +1000).
Options will have a text (1-40) and a value (the value selected by user).
User will select one (or more) of these options.
My conceptual design is:
I don't know how to associate an answer with an user.
How can I represent that relation?
Do I have another entity to represent option value?
This model will store questions and pre-made answers (offered answers) and allows them to be re-used in different surveys.
I have to represent question like this one:
This question is related to this one: Survey database design: first version. Are there errors?