store json array as json string in database

Question

I have a business object called Schoolyear which has a flags enum at the moment:

[Flags]
public enum VisibleDayOfWeek : int
{
    None = 0,
    Monday = 1,
    Tuesday = 2,
    Wednesday = 4,
    Thursday = 8,
    Friday = 16,
    Saturday = 32,
    Sunday = 64
}

For me this are value objects without identifiers they do not get an extra sql table. This would also be overkill.

Now I thought about saving these visible days (which the user can configure) as int value in the database. It works at the moment but reading/writing in the database and reading/writing those values into a business object and doing integration tests with that objects is a pain.

As I am having a javascript client consuming json data I thought this morning why not save the json array which I get from the browser directly as json string in the database. So the only thing I would have to do is json.parse on client side. And to do integration tests on server side I use the existing json.serialize/deserialize methods from my json library.

The visible days are changed during a year only 1,2 or 3 times not often. Per user there are 5 schoolyear datarow per 5 years maybe not much more. The visible days column would never be queried via sql select. The UI logic is done on client side.

So for me its a good idea to store the json array as json string in the sql database.

What do you think about my new approach? Do you see any negative side effects I have not thought about which I could repent again later.. ?

Answer 1

Reasons to not put JSON in a text field in a relational database:

1. You lose the ability to do queries that depend on the data in the JSON field.
2. As you do not describe your data to the SQL engine, your application/server code has the responsibility to validate the data and ensure that it can behave if the data becomes corrupted.

Reasons to put JSON in a text field in a relational database:

1. Efficiency (JOIN can be slow, and if you know that you will never need to query using the data in the field, you do not need to store it in a way that allows that).
2. Simplify implementation (Just ensure that you check (on the server) that the client gave you a valid JSON string).