EF Core集成Npgsql时List<NpgsqlRange<LocalDateTime>>字段无法映射如何解决

使用EF Core对接PostgreSQL时，引入了如下NuGet包：

• Npgsql.EntityFrameworkCore.PostgreSQL 5.0.2
• Npgsql.EntityFrameworkCore.PostgreSQL.NodaTime 5.0.2

实体类定义如下：

using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using Nest;

namespace Vepo.Domain
{
    [ElasticsearchType(RelationName = "eventitem", IdProperty = "Id")]
    public class EventItem : VeganItem<EventItemEstablishment>
    {
        [MaxLength(10)]
        public List<NpgsqlRange<LocalDateTime>> Dates { get; set; }
    }
}

启动程序后抛出如下异常：

InvalidOperationException: The property ‘EventItem.Dates’ could not be mapped, because it is of type List<NpgsqlRange<LocalDateTime>> which is not a supported primitive type or a valid entity type. Either explicitly map this property, or ignore it using the ‘[NotMapped]’ attribute or by using ‘EntityTypeBuilder.Ignore’ in ‘OnModelCreating’.

此前已经验证单独的LocalDateTime类型可以通过值转换器完成映射：

base.OnModelCreating(modelBuilder);
var localDateConverter = 
    new ValueConverter<LocalDate, DateTime>(v =>  
        v.ToDateTimeUnspecified(), 
        v => LocalDate.FromDateTime(v));

modelBuilder.Entity<Event>()
    .Property(e => e.Date)
    .HasConversion(localDateConverter);

但该方案不适用List<NpgsqlRange<LocalDateTime>>类型，且前端传入后端的参数格式为[{DateTime startDate, DateTime endDate}]，无法通过自定义值转换器适配。

问题出在NodaTime的注册方式错误，原有Startup.cs配置如下：

public void ConfigureServices(IServiceCollection services)
{
    services
    .AddDbContext<VepoContext>(opt => {
        opt
        .UseNpgsql(
            Configuration
            .GetConnectionString("DefaultConnection"))
            .EnableSensitiveDataLogging()
            .EnableDetailedErrors()
            .LogTo(Console.WriteLine);
    });
    
    NpgsqlConnection.GlobalTypeMapper.UseNodaTime();
}

只需将UseNodaTime()的调用挪到UseNpgsql的配置委托中即可，修改后的配置如下：

public void ConfigureServices(IServiceCollection services)
{
    services
    .AddDbContext<VepoContext>(opt => {
        opt
        .UseNpgsql(
            Configuration
            .GetConnectionString("DefaultConnection"), 
                o => o.UseNodaTime()
            )
            .EnableSensitiveDataLogging()
            .EnableDetailedErrors()
            .LogTo(Console.WriteLine);
    });
}

修改后无需额外自定义值转换器，EF Core即可自动完成List<NpgsqlRange<LocalDateTime>>类型到PostgreSQL数组+范围类型的映射，也可正常适配前端传入的时间范围参数格式。

内容的提问来源于stack exchange，提问作者BeniaminoBaggins