One to one relationship Mysql EF6 - mysql

Question

Hi there I've been banging my head now for two days and haven't been able to solve this one: I have this data structure:
[
{
"LocalObservationDateTime": "2019-12-12T19:50:00+02:00",
"EpochTime": 1576173000,
"WeatherText": "Thunderstorm",
"WeatherIcon": 15,
"HasPrecipitation": true,
"Reciprocation": "Rain",
"IsDayTime": false,
"Temperature": {
"Metric": {
"Value": 13.7,
"Unit": "C",
"UnitType": 17
},
"Imperial": {
"Value": 57,
"Unit": "F",
"UnitType": 18
}
}
}
]
I designed my data like this:
Table1:
Id,
LocalObservationDateTime,
EpochTime
WeatherText,
WeatherIcon,
HasPrecipitation,
PrecipitationType,
IsDayTime,
TemperatureId
Table2
TemperatureId,
ImperialId,
MetricId
Table3
Id,
Value,
Unit,
UnitType
I connected FKs tables 3 Id ImperialId and MetricId in Table 3 and TemperatureId in Table 2 to TemperatureId in table1
these are my models:
[Table("currentweather")]
public class CurrentWeather
{
[Key, Column("id")]
public int Id { get; set; }
[Column("locationid")]
public int LocationId { get; set; }
[Column("localobservationdatetime")]
public DateTime LocalObservationDateTime { get; set; }
[Column("epochtime")]
public long EpochTime { get; set; }
[Column("weathertext")]
public string WeatherText { get; set; }
[Column("weathericon")]
public int WeatherIcon { get; set; }
[Column("hasprecipitation")]
public bool HasPrecipitation { get; set; }
[Column("precipitationtype")]
public string PrecipitationType { get; set; }
[Column("isdaytime")]
public bool IsDayTime { get; set; }
[ForeignKey("Temperature")]
[Column("temperatureid")]
public int TemperatureId { get; set; }
[Column("mobilelink")]
public string MobileLink { get; set; }
[Column("link")]
public string Link { get; set; }
[NotMapped]
public Temperature Temperature { get; set; }
}
[Table("temperature")]
public class Temperature
{
[Key, Column("tepmeratureid")]
public int TemperatureId { get; set; }
[ForeignKey("Imperial")]
[Column("imperialid")]
public int ImperialId { get; set; }
[ForeignKey("Metric")]
[Column("metricid")]
public int MetricId { get; set; }
[NotMapped]
public CurrentWeather CurrentWeather { get; set; }
[NotMapped]
public TemperatureUnit Imperial { get; set; }
[NotMapped]
public TemperatureUnit Metric { get; set; }
}
public class TemperatureUnit
{
public double Value { get; set; }
public Unit Unit { get; set; }
public int UnitType { get; set; }
[NotMapped]
public Temperature Temperature { get; set; }
}
public enum Unit { C,F}
I am using Mysql and Net.core EF6
When adding data only table 1 gets the data but the other two don't HELP!!!

Answer 1

Your json object doesn't match your database tables, so you'll have to do some mapping of those properties.
Note: the below code leaves off several properties, but you should be able to follow this and add them in as needed.
First, you need to make your json string into an object. If passed in from a controller you can use model binding; otherwise you'll have to deserialize it. Here's an appropriate view model for that:
public class CurrentWeatherViewModel
{
public DateTime LocalObservartionTime { get; set; }
public int EpochTime { get; set; }
public string WeatherText { get; set; }
//additional props here
public TemperatureViewModel Temperature { get; set; }
}
public class TemperatureViewModel
{
public MetricViewModel Metric { get; set; }
public ImperialViewModel Imperial { get; set; }
}
public class MetricViewModel
{
public decimal Value { get; set; }
public string Unit { get; set; }
public int UnitType { get; set; }
}
public class ImperialViewModel
{
public decimal Value { get; set; }
public string Unit { get; set; }
public int UnitType { get; set; }
}
You can deserialize the json string into that object like this:
var jsonString = " {\"EpochTime\": 1576173000,\"WeatherText\": \"Thunderstorm\",\"WeatherIcon\": 15,\"HasPrecipitation\": true,\"Reciprocation\": \"Rain\",\"IsDayTime\": false,\"Temperature\": {\"Metric\": {\"Value\": 13.7,\"Unit\": \"C\",\"UnitType\": 17},\"Imperial\": {\"Value\": 57,\"Unit\": \"F\",\"UnitType\": 18}}}";
CurrentWeatherViewModel currentWeatherViewModel = Newtonsoft.Json.JsonConvert.DeserializeObject<CurrentWeatherViewModel>(jsonString);
Once it's deserialized into the viewmodel object, you can create your entities and save them to the db:
CurrentWeather currentWeather = new CurrentWeather
{
WeatherText = currentWeatherViewModel.WeatherText,
Temperature = new Temperature
{
Measurements = new Measurement[] {
new Measurement {
Unit = currentWeatherViewModel.Temperature.Metric.Unit,
UnitType = currentWeatherViewModel.Temperature.Metric.UnitType,
Value = currentWeatherViewModel.Temperature.Metric.Value,
},
new Measurement {
Unit = currentWeatherViewModel.Temperature.Imperial.Unit,
UnitType = currentWeatherViewModel.Temperature.Imperial.UnitType,
Value = currentWeatherViewModel.Temperature.Imperial.Value,
}
}
}
};
db.CurrentWeathers.Add(currentWeather);
db.SaveChanges();
Here's the entity classes:
public class CurrentWeather
{
public int Id { get; set; }
public DateTime? LocalObservartionTime { get; set; }
public int EpochTime { get; set; }
public string WeatherText { get; set; }
//additional props here
public virtual Temperature Temperature { get; set; }
}
public class Temperature
{
public int Id { get; set; }
//relationship
public int CurrentWeatherId { get; set; }
//relationship
public virtual ICollection<Measurement> Measurements { get; set; }
}
public class Measurement
{
public int Id { get; set; }
public decimal Value { get; set; }
public string Unit { get; set; }
public int UnitType { get; set; }
//relationship
public int TemperatureId { get; set; }
public virtual Temperature Temperature { get; set; }
}