NodaTime database json serialization

Question

I'm saving list of schedules in my jsonb column in postgres database and I'm having problems with LocalDate NodaTime type.

Here is my object that is being serialized (actually List<Schedule> is serialized and stored in database)

public class Schedule
{
    public LocalTime? Start { get; set; }
    public LocalTime? End { get; set; }
}

This is what's get stored in the database

[
    {
        "End": {
            "Hour": 10,
            "Minute": 0,
            "Second": 0,
            "TickOfDay": 360000000000,
            "Millisecond": 0,
            "TickOfSecond": 0,
            "NanosecondOfDay": 36000000000000,
            "ClockHourOfHalfDay": 10,
            "NanosecondOfSecond": 0
        },
        "Start": {
            "Hour": 8,
            "Minute": 0,
            "Second": 0,
            "TickOfDay": 288000000000,
            "Millisecond": 0,
            "TickOfSecond": 0,
            "NanosecondOfDay": 28800000000000,
            "ClockHourOfHalfDay": 8,
            "NanosecondOfSecond": 0
        }
    }
]

Which seems pretty fine to me, but the problem is when I'm fetching the data from database my LocalDate's are '00:00:00'.

Serialization/Deserialization is done using

var converter = new ValueConverter<T, string>
(
    v => JsonConvert.SerializeObject(v),
    v => JsonConvert.DeserializeObject<T>(v) ?? null
);

It looks like you're just using default serialization, which is going to struggle when *deserializing* to immutable value types. It looks like you're probably using Json.NET, so use the `NodaTime.Serialization.JsonNet` library to perform appropriate serialization and deserialization. (This will make the stored data *much* more readable too...) — Jon Skeet, Mar 30 '20 at 08:27
Exactly! Dunno why I thought that "whole object" serialization was correct, once I've added `JsonConvert.SerializeObject(r, NodaConverters.LocalTimeConverter)` from `NodaTime.Serialization.JsonNet`, it's serialized as string and correctly deserialized. Thanks @JonSkeet, will close the issue. — zhuber, Mar 30 '20 at 08:39

zhuber · Accepted Answer · 2020-03-30T09:11:51.917

I've added the NodaTime.Serialization.JsonNet as suggested in the comments and changed the converter for Entity Framework to:

var converter = new ValueConverter<T, string>
(
    v => JsonConvert.SerializeObject(v, NodaConverters.LocalTimeConverter),
    v => JsonConvert.DeserializeObject<T>(v, NodaConverters.LocalTimeConverter) ?? null
);

This now correctly serializes to string and successfully deserializes.

[{"End": "10:00:00", "Start": "09:00:00"}]

NodaTime database json serialization

1 Answers1