c# - 找不到实体类型。确保实体类型已添加到模型中

Question

我是 ASP.NET Core 的新手，我正在尝试将实体插入到从简单的现有 MariaDB 数据库搭建的 Entity Framework Core 模型中。

这是实体模型:

    public class ScrapeAsincroni
    {
        public int Id { get; set; }
        public string Paese { get; set; }
        public string Engine { get; set; }
        public string Keywords { get; set; }
    }

这是应该添加实体的 Controller 操作:

    public JsonResult create(string paese, string engine, string keywords)
        {
            ScrapeAsincroni scrapeAsincrono = new ScrapeAsincroni {
                Paese = paese,
                Engine = engine,
                Keywords = keywords
            };
            _context.Add(scrapeAsincrono);

            try
            {
                _context.SaveChangesAsync();
            }
            catch (Exception ex)
            {
                return Json(new Dictionary<string, int?> { { "id", null } });
            }
            return Json(new Dictionary<string, int?>{ {"id", scrapeAsincrono.Id} });
        }

数据库上下文 (_context) 已在 Controller 的构造函数中初始化。线路

 _context.Add(scrapeAsincrono);

抛出以下异常:

System.InvalidOperationException: The entity type 'ScrapeAsincroni' was not found. Ensure that the entity type has been added to the model.

这是与该模型相关的模型构建器代码

   public partial class ScraperDbContext : DbContext
    {
        public ScraperDbContext()
        {
        }

        public ScraperDbContext(DbContextOptions<ScraperDbContext> options)
            : base(options)
        {
        }

        public virtual DbSet<ScrapeAsincroni> ScrapeAsincroni { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            if (!optionsBuilder.IsConfigured)
            {
                #warning To protect potentially sensitive information in your connection string, you should move it out of source code. See http://go.microsoft.com/fwlink/?LinkId=723263 for guidance on storing connection strings.
                optionsBuilder.UseMySql("server=#.#.#.#;port=####;user=####;password=####;database=####", x => x.ServerVersion("10.3.25-mariadb"));
            }
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<ScrapeAsincroni>(entity =>
            {
                entity.HasComment("Informazioni su una ricerca asincrona dello Scraper");

                entity.Property(e => e.Id)
                    .HasColumnName("id")
                    .HasColumnType("int(11)");

                entity.Property(e => e.Engine)
                    .HasColumnName("engine")
                    .HasColumnType("varchar(255)")
                    .HasCharSet("utf8")
                    .HasCollation("utf8_general_ci");

                entity.Property(e => e.Keywords)
                    .IsRequired()
                    .HasColumnName("keywords")
                    .HasColumnType("text")
                    .HasCharSet("utf8")
                    .HasCollation("utf8_general_ci");

                entity.Property(e => e.Paese)
                    .HasColumnName("paese")
                    .HasColumnType("varchar(255)")
                    .HasCharSet("utf8")
                    .HasCollation("utf8_general_ci");
            });

            OnModelCreatingPartial(modelBuilder);
        }

        partial void OnModelCreatingPartial(ModelBuilder modelBuilder);
    }         

我似乎不明白为什么会这样，也无法在线找到任何解决方案。

Answer 1

添加

public DbSet<ScrapeAsincroni> ScrapeAsincronis { get; set; }

在您的上下文文件中，用于将实体添加到您的模型。