使用枚举器进行映射

本文关键字：映射 枚举 | 更新日期: 2023-09-27 18:28:34

我有一个带有一列char（2）的表

CREATE TABLE COMPANY (
    EMP_ID            INTEGER NOT NULL,
    EMP_TYPE          CHAR(2) NOT NULL,
    EMP_NM            VARCHAR(35) NOT NULL
);

使用实体框架，我想用枚举映射实体。

public class Company
{
    public Company ()
    {
        Id = null;
        Type = Enums.EnumType.TipoCompany.Matriz;
        Name = string.Empty;
    }
    public int? Id{ get; set; }
    public string Name{ get; set; }
    public Enums.EnumType.TipoCompany TipoCompany { get; set; }
}
public class CompanyMap : EntityTypeConfiguration<Company>
{
    public CompanyMap()
    {
        ToTable("COMPANY");
        HasKey(t => new { t.Id});
        Property(t => t.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.None).HasColumnName("EMP_ID");
        Property(t => t.Name)
            .IsRequired()
            .HasMaxLength(35)
            .HasColumnType("Varchar")
            .HasColumnName("EMP_NM");
        Property(t => t.TypeCompany)
          .IsRequired()
          .HasColumnType("Varchar")
          .HasColumnName("EMP_TYPE");
    }
}
public class EnumTypeCompany
{
    public enum TypeCompany
    {
        [Description("Matriz")]
        Matriz = 01,
        [Description("Filial")]
        Filial = 02,
    }
}

我得到错误：

Contexto.Type[Nullable=False,DefaultValue=]' of member 'TypoCompany' in type 'Contexto.Company' is not compatible with 'FirebirdClient.varchar

如何将varchar转换为枚举？？？

使用枚举器进行映射

如果在EMP_TYPE字段中使用int而不是varchar，则问题应该得到解决。当您从数据库中获取数据时，int字段将自动转换到您的枚举中。

更新

public class Company
{
    public Company ()
    {
        Id = null;
        TipoCompanyString = ((int)Enums.EnumType.TipoCompany.Matriz).ToString();
        TipoCompany = Enums.EnumType.TipoCompany.Matriz;
        Name = string.Empty;
    }
    public int? Id { get; set; }
    public string Name { get; set; }
    public string TipoCompanyString { get; set; }
    public Enums.EnumType.TipoCompany TipoCompany { 
        get {
            var intValue = Convert.ToInt32(TipoCompanyString);
            return (Enums.EnumType.TipoCompany)intValue;
        }
        set {
            TipoCompanyString = ((int)value).ToString()
        }
    }
}
public class CompanyMap : EntityTypeConfiguration<Company>
{
    public CompanyMap()
    {
        ToTable("COMPANY");
        HasKey(t => new { t.Id});
        Property(t => t.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.None).HasColumnName("EMP_ID");
        Property(t => t.Name)
            .IsRequired()
            .HasMaxLength(35)
            .HasColumnType("Varchar")
            .HasColumnName("EMP_NM");
        Property(t => t.TipoCompanyString)
            .IsRequired()
            .HasColumnType("Varchar")
            .HasColumnName("EMP_TYPE");
    }
}
public class EnumTypeCompany
{
    public enum TypeCompany
    {
        [Description("Matriz")]
        Matriz = 01,
        [Description("Filial")]
        Filial = 02,
    }
}

在c#中，不能有enum:string，只能有int、byte等。您可以做的是制作一个"伪"枚举：

public static class FakeEnum
{
  public static readonly OptionOne = "blabla";
  public static readonly OptionTwo = "random";
}

字符串值将是数据库中EMP_TYPE字段的值。您可以像使用字符串枚举一样使用它，例如在checks:中

Company company = db.Companies.First();
if(company.Type == FakeEnum.OptionOne) //company.Type is really "blabla" in db
  DoStuff();
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