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我在 Pomelo 5.0 中使用了最新版本的 json 实现，并将我的 maria 服务器配置为使用 microsoft json 序列化。

  var serverVersion = new MariaDbServerVersion(new Version(10, 3, 0));

    services.AddDbContext<BusinessManagementDbContext>(options =>
    {
      options.UseMySql(databaseConfiguration.ConnectionString, serverVersion, m =>
     {
       m.UseMicrosoftJson(MySqlCommonJsonChangeTrackingOptions.FullHierarchyOptimizedSemantically);
       m.EnableRetryOnFailure();
     });
      
      options.EnableSensitiveDataLogging(true);
    });

我可以将我的 POCO 保存在我的数据库中，但是当我尝试查询我的数据时，我得到一个空对象。这是我的数据： HeidySQL 数据

我的查询非常简单，但我认为我没有使用正确的方式进行 json 查询。

await Context.ValidatedSaleInvoices.AsNoTracking().FirstOrDefaultAsync(x => x.Id == id);

我的数据和我的属性“内容”之间似乎没有反序列化。

我怎样才能做到这一点 ？

谢谢，

编辑

我的模型是：

     public class ValidateSaleInvoiceEntity
  {
    public int Id { get; set; }

    public ValidateSaleInvoiceContent Content { get; set; }
  }

  public class ValidateSaleInvoiceContent
  {
    public string BusinessName { get; set; }

    public DateTime Date { get; internal set; }

    public string Number { get; internal set; }

    public Address Address { get; internal set; }

    public List<ValidateSaleInvoiceLineEntity> Lines { get; internal set; } = new List<ValidateSaleInvoiceLineEntity>();
  }

  public class ValidateSaleInvoiceLineEntity
  {
    public string Description { get; internal set; }

    public decimal Quantity { get; internal set; } 

    public decimal UnitPriceVatExcluded { get; internal set; } 

    public decimal VatRate { get; internal set; }
  }

我的 json 结果是这样的（空的，就像没有反序列化一样：{ "BusinessName":"", "Date":"", "Number":"" etc.}

我的老板停止了我关于 MariaDB Json 实现的 poc，所以我不得不回到这个好老朋友纯 sql 专栏：/。这就是为什么我没有完整的 json 结果。对不起

4

1 回答 1

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对于将 JSON 自动序列化/反序列化为 POCO 的属性，您需要告诉 Pomelo，该属性的表列是 MySQL/MariaDB 类型json：

public class ValidateSaleInvoiceEntity
{
    public int Id { get; set; }

    [Column(TypeName = "json")] // <-- this is one way to do it
    public ValidateSaleInvoiceContent Content { get; set; }
}

public class MyContext : DbContext
{
    // ...
    
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<ValidateSaleInvoiceEntity>()
            .Property(e => e.Content)
                 .HasColumnType("json"); // <-- this is another way to do it
    }
}

这是一个完整的控制台项目：

using System.ComponentModel.DataAnnotations.Schema;
using System.Diagnostics;
using System.Linq;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;

namespace IssueConsoleTemplate
{
    // EF Core entities:
    public class IceCream
    {
        public int IceCreamId { get; set; }
        public string Name { get; set; }
        
        // Either use this data annotation, or the corresponding Fluent API call (see
        // OnModelCreating), to explicitly mark the column type as JSON.
        [Column(TypeName = "json")]
        public IceCreamDetails Details { get; set; }
    }

    // JSON class:
    public class IceCreamDetails
    {
        public int Kilojoule { get; set; }
        public int Rating { get; set; }
    }
    
    public class Context : DbContext
    {
        public DbSet<IceCream> IceCreams { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            if (!optionsBuilder.IsConfigured)
            {
                var connectionString = "server=127.0.0.1;port=3306;user=root;password=;database=So68020732";
                var serverVersion = ServerVersion.AutoDetect(connectionString);
                
                optionsBuilder.UseMySql(connectionString, serverVersion, options => options
                        .UseMicrosoftJson(MySqlCommonJsonChangeTrackingOptions.FullHierarchyOptimizedSemantically))
                    .UseLoggerFactory(
                        LoggerFactory.Create(
                            configure => configure
                                .AddConsole()
                                .AddFilter(level => level >= LogLevel.Information)))
                    .EnableSensitiveDataLogging()
                    .EnableDetailedErrors();
            }
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<IceCream>(
                entity =>
                {
                    // Either use this Fluent API call, or the corresponding data annotation
                    // (see the IceCreamDetails class), to explicitly mark the column type as JSON.
                    entity.Property(e => e.Details)
                        .HasColumnType("json");
                    
                    entity.HasData(
                        new IceCream {IceCreamId = 1, Name = "Vanilla", Details = new IceCreamDetails { Kilojoule = 865, Rating = 9 }},
                        new IceCream {IceCreamId = 2, Name = "Chocolate", Details = new IceCreamDetails { Kilojoule = 903, Rating = 10 }});
                });
        }
    }

    internal static class Program
    {
        private static void Main()
        {
            using var context = new Context();

            context.Database.EnsureDeleted();
            context.Database.EnsureCreated();

            var iceCreams = context.IceCreams
                .OrderBy(i => i.IceCreamId)
                .ToList();

            Trace.Assert(iceCreams.Count == 2);
            Trace.Assert(iceCreams[0].Details.Kilojoule == 865);
            Trace.Assert(iceCreams[1].Details.Rating == 10);
        }
    }
}

您可以在我们的存储库中找到最全面的 JSON 示例代码（参见JSON mapping and query scenarios章节）。

于 2021-06-23T21:19:26.330 回答