c# - EF 核心导航属性未加载

Question

我正在修改我的应用程序，以便能够指定要加载到存储库中的导航属性。

模型:Team 和 TeamTunerUser 可以在 domain entites 中找到.

存储库:

namespace Sppd.TeamTuner.Infrastructure.DataAccess.EF.Repositories
{
    internal class Repository<TEntity> : IRepository<TEntity>
        where TEntity : BaseEntity
    {
        /// <summary>
        ///     Gets the entity set.
        /// </summary>
        protected DbSet<TEntity> Set => Context.Set<TEntity>();

        /// <summary>
        ///     Gets the DB context.
        /// </summary>
        protected TeamTunerContext Context { get; }

        public Repository(TeamTunerContext context)
        {
            Context = context;
        }

        public async Task<TEntity> GetAsync(Guid entityId, IEnumerable<string> includeProperties = null)
        {
            TEntity entity;
            try
            {
                entity = await GetQueryableWithIncludes(includeProperties).SingleAsync(e => e.Id == entityId);
            }
            catch (InvalidOperationException)
            {
                throw new EntityNotFoundException(typeof(TEntity), entityId.ToString());
            }

            return entity;
        }

        protected IQueryable<TEntity> GetQueryableWithIncludes(IEnumerable<string> includeProperties = null)
        {
            var queryable = Set;

            if (includeProperties == null)
            {
                return queryable;
            }

            foreach (var propertyName in includeProperties)
            {
                queryable.Include(propertyName);
            }

            return queryable;
        }
    }
}

测试:

    [Fact]
    public async Task TestNavigationPropertyLoading()
    {
        // Arrange
        var teamId = Guid.Parse(TestingConstants.Team.HOLY_COW);

        // Act
        Team createdTeamWithoutUsers;
        Team createdTeamWithUsers;
        using (var scope = ServiceProvider.CreateScope())
        {
            var teamRepository = scope.ServiceProvider.GetService<IRepository<Team>>();

            createdTeamWithoutUsers = await teamRepository.GetAsync(teamId);
            createdTeamWithUsers = await teamRepository.GetAsync(teamId, new[] {nameof(Team.Users)});
        }

        // Assert
        Assert.Null(createdTeamWithoutUsers.Leader);
        Assert.False(createdTeamWithoutUsers.Users.Any());
        Assert.False(createdTeamWithUsers.CoLeaders.Any());

        Assert.NotNull(createdTeamWithUsers.Leader);
        Assert.True(createdTeamWithUsers.Users.Any());
        Assert.True(createdTeamWithUsers.CoLeaders.Any());
    }

我的问题是 Users 导航属性从未加载，第二个断言 block 失败。

团队在这里配置(class):

    private static void ConfigureTeam(EntityTypeBuilder<Team> builder)
    {
        ConfigureDescriptiveEntity(builder);

        builder.HasMany(e => e.Users)
               .WithOne(e => e.Team);

        // Ignore calculated properties
        builder.Ignore(e => e.Members)
               .Ignore(e => e.Leader)
               .Ignore(e => e.CoLeaders);
    }

(调试)日志不包含任何有用的信息，除了我看到加载导航属性所需的连接没有在 SQL 级别执行:

2019-04-11 16:02:43,896 [14] DEBUG Microsoft.EntityFrameworkCore.Database.Connection - Opening connection to database 'Sppd.TeamTuner-TEST' on server '.\SQLEXPRESS'.
2019-04-11 16:02:43,901 [14] DEBUG Microsoft.EntityFrameworkCore.Database.Connection - Opened connection to database 'Sppd.TeamTuner-TEST' on server '.\SQLEXPRESS'.
2019-04-11 16:02:43,903 [14] DEBUG Microsoft.EntityFrameworkCore.Database.Command - Executing DbCommand [Parameters=[@__entityId_0='?' (DbType = Guid)], CommandType='Text', CommandTimeout='30']
SELECT TOP(2) [m].[Id], [m].[Avatar], [m].[CreatedById], [m].[CreatedOnUtc], [m].[DeletedById], [m].[DeletedOnUtc], [m].[Description], [m].[FederationId], [m].[IsDeleted], [m].[ModifiedById], [m].[ModifiedOnUtc], [m].[Name]
FROM [Team] AS [m]
WHERE ([m].[IsDeleted] = 0) AND ([m].[Id] = @__entityId_0)
2019-04-11 16:02:43,920 [12] INFO  Microsoft.EntityFrameworkCore.Database.Command - Executed DbCommand (16ms) [Parameters=[@__entityId_0='?' (DbType = Guid)], CommandType='Text', CommandTimeout='30']
SELECT TOP(2) [m].[Id], [m].[Avatar], [m].[CreatedById], [m].[CreatedOnUtc], [m].[DeletedById], [m].[DeletedOnUtc], [m].[Description], [m].[FederationId], [m].[IsDeleted], [m].[ModifiedById], [m].[ModifiedOnUtc], [m].[Name]
FROM [Team] AS [m]
WHERE ([m].[IsDeleted] = 0) AND ([m].[Id] = @__entityId_0)
2019-04-11 16:02:43,945 [12] DEBUG Microsoft.EntityFrameworkCore.Database.Command - A data reader was disposed.
2019-04-11 16:02:43,985 [12] DEBUG Microsoft.EntityFrameworkCore.Database.Connection - Closing connection to database 'Sppd.TeamTuner-TEST' on server '.\SQLEXPRESS'.
2019-04-11 16:02:43,988 [12] DEBUG Microsoft.EntityFrameworkCore.Database.Connection - Closed connection to database 'Sppd.TeamTuner-TEST' on server '.\SQLEXPRESS'.
2019-04-11 16:02:45,054 [12] DEBUG Microsoft.EntityFrameworkCore.Database.Connection - Opening connection to database 'Sppd.TeamTuner-TEST' on server '.\SQLEXPRESS'.
2019-04-11 16:02:45,057 [12] DEBUG Microsoft.EntityFrameworkCore.Database.Connection - Opened connection to database 'Sppd.TeamTuner-TEST' on server '.\SQLEXPRESS'.
2019-04-11 16:02:45,060 [12] DEBUG Microsoft.EntityFrameworkCore.Database.Command - Executing DbCommand [Parameters=[@__entityId_0='?' (DbType = Guid)], CommandType='Text', CommandTimeout='30']
SELECT TOP(2) [m].[Id], [m].[Avatar], [m].[CreatedById], [m].[CreatedOnUtc], [m].[DeletedById], [m].[DeletedOnUtc], [m].[Description], [m].[FederationId], [m].[IsDeleted], [m].[ModifiedById], [m].[ModifiedOnUtc], [m].[Name]
FROM [Team] AS [m]
WHERE ([m].[IsDeleted] = 0) AND ([m].[Id] = @__entityId_0)
2019-04-11 16:02:45,067 [14] INFO  Microsoft.EntityFrameworkCore.Database.Command - Executed DbCommand (7ms) [Parameters=[@__entityId_0='?' (DbType = Guid)], CommandType='Text', CommandTimeout='30']
SELECT TOP(2) [m].[Id], [m].[Avatar], [m].[CreatedById], [m].[CreatedOnUtc], [m].[DeletedById], [m].[DeletedOnUtc], [m].[Description], [m].[FederationId], [m].[IsDeleted], [m].[ModifiedById], [m].[ModifiedOnUtc], [m].[Name]
FROM [Team] AS [m]
WHERE ([m].[IsDeleted] = 0) AND ([m].[Id] = @__entityId_0)
2019-04-11 16:02:45,092 [14] DEBUG Microsoft.EntityFrameworkCore.Database.Command - A data reader was disposed.
2019-04-11 16:02:45,143 [14] DEBUG Microsoft.EntityFrameworkCore.Database.Connection - Closing connection to database 'Sppd.TeamTuner-TEST' on server '.\SQLEXPRESS'.
2019-04-11 16:02:45,153 [14] DEBUG Microsoft.EntityFrameworkCore.Database.Connection - Closed connection to database 'Sppd.TeamTuner-TEST' on server '.\SQLEXPRESS'.

我尝试过的:

• 不要指定字符串，而是指定要加载的导航属性的表达式:

  protected IQueryable<TEntity> GetQueryableWithIncludes(IEnumerable<string> includeProperties = null)
  {
      var queryable = Set;
  
      if (includeProperties == null)
      {
          return queryable;
      }
  
      if (typeof(TEntity) == typeof(Team))
      {
          // TODO: Remove this block once it works by including by string properties
          foreach (var propertyName in includeProperties)
          {
              if (propertyName == "Users")
  
              {
                  queryable.OfType<Team>().Include(entity => entity.Users);
              }
          }
      }
      else
      {
          foreach (var propertyName in includeProperties)
          {
              queryable.Include(propertyName);
          }
      }
  
      return queryable;
  }
  

• 也为用户实体显式配置关系:

  private static void ConfigureTeamTunerUser(EntityTypeBuilder<TeamTunerUser> builder)
  {
      ConfigureDescriptiveEntity(builder);
  
      builder.HasMany(e => e.CardLevels)
             .WithOne(e => e.User);
  
      builder.HasOne(e => e.Team)
             .WithMany(e => e.Users);
  
      // Indexes and unique constraint
      builder.HasIndex(e => e.Name)
             .IsUnique();
      builder.HasIndex(e => e.SppdName)
             .IsUnique();
      builder.HasIndex(e => e.Email)
             .IsUnique();
  }
  

我错过了什么？

Answer 1

Include/ThenInclude (以及所有其他 EF Core Queryable 扩展)就像常规 LINQ Queryable修改源 Select 的方法( Where 、 OrderBy 、 IQueryable<> 等)并返回修改后的IQueryable<> .

在这里你只是忘记了使用结果查询，所以

queryable.Include(propertyName);

效果与

相同

queryable.Where(e => false);

即没有效果。

只需将代码更改为

queryable = queryable.Include(propertyName);