如何在 MVC 4 上创建特定模型的历史模型

Question

在使用 Entity Framework 和 MVC 4 Razor 创建模型方面我还是个新手。我对如何保存模型的历史有疑问。如何创建具有特定表或字段历史记录的模型？例如：如果我想创建关于学校变化的历史。我仍然不清楚我将如何创建保存历史的模型。我必须如何在具有相同数据的不同模型上执行保存功能？

非常感谢您。

如果有人可以提供模型和模型历史及其运作方式的简单示例，我将不胜感激。就像销售或销售历史一样。

这是我的代码

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一对多 公共课儿童 { [钥匙] 公共 int ChildID { 获取；放; }

    [Required,Display(Name="Project Code")]
    public string ProjectCode { get; set; }

    public string Status { get; set; }

    [DataType(DataType.Date)]
    public DateTime StatusDate { get; set; }

    public string FamilyName { get; set; }
    public string GivenName { get; set; }
    public string MiddleName { get; set; }

    [DataType(DataType.Date)]
    public DateTime Birthdate { get; set; }

    public string Gender {get;set;}
    public string Address { get; set; }
    public string Section { get; set; }
    public int SchoolLevelID { get; set; }
    public int SchoolYearID { get; set; }
    public int AreaID { get; set; }
    public int SchoolID { get; set; }
    public int GradeLevelID { get; set; }

    //Foreign Key - One to Many 
    public virtual SchoolLevel SchoolLevel { get; set; }
    public virtual SchoolYear SchoolYear { get; set; }
    public virtual Area Area { get; set; }
    public virtual School School { get; set; }
    public virtual GradeLevel GradeLevel{get;set;}

    //Child is foreign key at the table
    public virtual ICollection<Guardian> Guardians { get; set; }

}


public class SchoolLevel
{
    public int SchoolLevelID { get; set; }
    public string SchoolLevelName { get; set; }

    public virtual ICollection<Child> Children { get; set; }
}

public class SchoolYear
{
    public int SchoolYearID { get; set; }
    public string SchoolYearName { get; set; }

    public virtual ICollection<Child> Children{get;set;}
}

public class Area
{
    public int AreaID{get;set;}
    public string AreaName { get; set; }

    public virtual ICollection<Child> Children{get;set;}
}

public class School
{
    public int SchoolID { get; set; }
    public string SchoolName{get;set;}

    public virtual ICollection<Child> Children { get; set; }
}
public class GradeLevel
{
    public int GradeLevelID{get;set;}
    public string GradeLevelName { get; set; }

    public virtual ICollection<Child> Children { get; set; }
}


public class ChildDbContext : DbContext
{
    public DbSet<Child> Children { get; set; }
    public DbSet<SchoolLevel> SchoolLevels { get; set; }
    public DbSet<SchoolYear> SchoolYears { get; set; }
    public DbSet<Area> Areas { get; set; }
    public DbSet<School> Schools { get; set; }
    public DbSet<GradeLevel> GradeLevels { get; set; }
    public DbSet<Guardian> Guardians { get; set; }
}

Answer 1

您可以使用这种方法：创建一个History 模型。这包含 1 个变化，例如 o log。

public class History 
{
    public int HistoryId { get; set; }

    public int ModelType { get; set; }  //it is ModelTypeEnum value.
    public int ModelId { get; set; }
    public string PropertyName { get; set; }
    public string Propertyvalue {get;set;}
    public DateTime ChangeDate { get; set; }

    public int ChangedUserId { get; set; }
}

和枚举：

public enum ModelTypeEnum
{
    Child =1,
    SchoolLevel = 2,
    //etc.. 
};

例如，当您编辑 1 个Child 实体时，将更改的属性名称和值、id、类型和其他（ChangeDate、ChangedUserId）传递给History 并保存历史记录。如果 3 个属性将更改，您应该保存 3 个历史实体。然后，您可以按 ModelId、ChangedUserId 等加载（过滤）历史记录。