如何使用 C# 从 SQL Server 检索点？

Question

我在我的 sql server 上使用空间数据类型，我想从我的 sql server 检索这些数据到我的实体类，它返回错误 ".NET 数值，如正无穷和负无穷大写为有效的 JSON。” 当我尝试从我的数据库中获取值时。

坐标是我想从我的数据库返回的值。我正在使用来自 NetTopologySuite 的 Geography 数据类型，并且我正在从我的实体类中插入一个点。

我正在使用的课程代码：

public class Address : EntityBase<int>
{
    public Address () {}

    public Address(string district, string street, int number, string complement, string zipCode, 
    string cityDescription, string stateDescription, Point coordinates, int countryId, byte stateId, int cityId)
    {
        District = district;
        Street = street;
        Number = number;
        Complement = complement;
        ZipCode = zipCode;
        CityDescription = cityDescription;
        StateDescription = stateDescription;
        Coordinates = coordinates;
        CountryId = countryId;
        StateId = stateId;
        CityId = cityId;
    }

    public string District { get; set; }
    public string Street { get; set; }
    public int Number { get; set; }
    public string Complement { get; set; }
    public string ZipCode { get; set; }
    public string CityDescription { get; set; }
    public string StateDescription { get; set; }
    public virtual Point Coordinates { get; set; }
    public int CountryId { get; set; }
    public byte StateId { get; set; }
    public int CityId { get; set; }
    public int? CustomerId { get; set; }
    public int? StoreId { get; set; }
    public int? ProfessionalId { get; set; }
}

以及表的sql server代码：

CREATE TABLE Address(
    Id INT PRIMARY KEY IDENTITY(1, 1),
    District VARCHAR(50) NOT NULL, -- Bairro
    Street VARCHAR(100) NOT NULL, -- Rua
    --Description VARCHAR(100) NOT NULL,
    Number INT,
    Complement VARCHAR(100),
    ZipCode VARCHAR(20) NOT NULL,
    CityDescription VARCHAR(100),
    StateDescription VARCHAR(100),
    Coordinates GEOGRAPHY,
    
    CountryId INT FOREIGN KEY REFERENCES Country(Id) NOT NULL,
    StateId TINYINT FOREIGN KEY REFERENCES State(Id),
    CityId INT FOREIGN KEY REFERENCES City(Id),
    CustomerId INT FOREIGN KEY REFERENCES Customer(Id),
    StoreId INT FOREIGN KEY REFERENCES Store(Id),
    ProfessionalId INT FOREIGN KEY REFERENCES Professional(Id),

    INDEX IndexAddressCountryId NONCLUSTERED (CountryId),
    INDEX IndexAddressStateId NONCLUSTERED (StateId),
    INDEX IndexAddressCityId NONCLUSTERED (CityId),
    INDEX IndexAddressCustomerId NONCLUSTERED (CustomerId),
    INDEX IndexAddressStoreId NONCLUSTERED (StoreId),
    INDEX IndexAddressProfessionalId NONCLUSTERED (ProfessionalId)
)

有什么方法可以从中检索 Point 值吗？像功能 OnModelCreating 上的配置或其他什么？我只能从中检索经度和纬度吗？

我是空间数据的新手，所以我不太了解它。提前感谢您帮助我:)

---

编辑 1：

这是我得到的异常错误：

实体库：

namespace CodenApp.Framework.Core.Entities
{
    public abstract class EntityBase<T>
    {
        public T Id { get; set; }
    }
}

还有我用来处理异常的两个函数：

public async Task InvokeAsync(HttpContext httpContext)
{
    try
    {
        await _next(httpContext);
    }
    catch (Exception ex)
    {
        _logger.LogError(ex, ex.ToString());                
        await HandleExceptionAsync(httpContext, ex);
    }
}


protected override Task HandleExceptionAsync(HttpContext context, Exception exception)
{
    if(context == null)
        throw new ArgumentNullException(nameof(context));
    if(exception == null)
        throw new ArgumentNullException(nameof(exception));

    context.Response.ContentType = "application/json";
    context.Response.StatusCode = (int)HttpStatusCode.BadRequest;
    return context.Response.WriteAsync(ApiCatch.Log(exception).ToString());
}

我用来转换为Point的代码：

public static Point ConvertToGeometry(string coordinatesAux)
{
    if(coordinatesAux == null)
        throw new NullReferenceException();

    NumberFormatInfo formatProvider = new NumberFormatInfo();
    formatProvider.NumberGroupSeparator = ".";
            
    var currentLocation = new Point(new Coordinate(
                                        Convert.ToDouble(coordinatesAux.Substring(0, coordinatesAux.IndexOf(",")), formatProvider), 
                                        Convert.ToDouble(coordinatesAux.Substring(coordinatesAux.IndexOf(",") + 1), formatProvider))) { SRID = 4326 };
            
    return currentLocation;                                                            
}

Answer 1

您可以简单地 JSON 忽略导致问题的属性并创建以可接受的格式显示值的属性。 这是我的做法：

public class LocationResult
{
    public Guid id { get; set; }
    [JsonIgnore]
    public GeoCoordinate geo { get; set; }
    public double latitude
    {
        get
        {
            return geo.Latitude;
        }
    }
    public double longitude
    {
        get
        {
            return geo.Longitude;
        }
    }
}

请注意：我知道这是针对与上面列出的对象类型不同的对象类型，但是该方法仍然适用于调整后的属性。

Answer 2

正如Panagiotis Kanavos在cmets中所说，为了解决这种情况我需要添加NuGet包NetTopologySuite.IO.GeoJSON4STJ并更改文件Startup.cs以接收包给出的更改。

ConfigureServices 函数内 Startup.cs 的变化：

services.AddControllers(options =>
{
    options.ModelMetadataDetailsProviders.Add(new SuppressChildValidationMetadataProvider(typeof(Point))); 
    options.ModelMetadataDetailsProviders.Add(new SuppressChildValidationMetadataProvider(typeof(Coordinate))); 
    options.ModelMetadataDetailsProviders.Add(new SuppressChildValidationMetadataProvider(typeof(LineString))); 
    options.ModelMetadataDetailsProviders.Add(new SuppressChildValidationMetadataProvider(typeof(MultiLineString))); 
});

services.AddControllers().AddJsonOptions(options =>
{
    var geoJsonConverterFactory = new GeoJsonConverterFactory();
    options.JsonSerializerOptions.Converters.Add(geoJsonConverterFactory);
});

services.AddSingleton(NtsGeometryServices.Instance);

并将 IOptions 添加到我的控制器中：

private readonly IOptions<JsonOptions> _jsonOptions;
public StoreController(IAsyncRepository<Store, int> repository, StoreHandler handler, IOptions<JsonOptions> jsonOptions) : base(repository)
{
    _handler = handler;
    _orders = new Expression<Func<Store, object>>[] { x => x.Id };
    _jsonOptions = jsonOptions;
}

所以在这个wiki.