c# - 实体框架：从迁移更改中排除审计属性

Question

我有一个由实体框架驱动的数据访问层的解决方案。一切正常，大约有 57 个实体。每个实体都继承自 EntityBase 类，该类包含仅在记录发生更改时才更新的审计字段。但是，由于某种原因，当我执行迁移时，我的记录似乎已被修改，这会更新实体审计字段，并使我的迁移过程每次需要 24 分钟才能运行。一张表种子数据并有 115000 行，每次运行“更新”。

实体库：

public abstract class EntityBase
    {
        [Required]
        [MaxLength(200)]
        public string CreatedBy { get; set; }
        [Required]
        public DateTime DateCreated { get; set; }
        [MaxLength(200)]
        public string UpdatedBy { get; set; }
        public DateTime? DateUpdated { get; set; }
        [Timestamp]
        public byte[] RowVersion { get; set; }

    }

如何在 Context 类中更新审计字段：

public override int SaveChanges()
        {
            try
            {
                SetAudit();

                return base.SaveChanges();
            }
            catch (DbEntityValidationException ex)
            {
                var sb = new StringBuilder();

                foreach (var failure in ex.EntityValidationErrors)
                {
                    sb.AppendFormat("{0} failed validation\n", failure.Entry.Entity.GetType());
                    foreach (var error in failure.ValidationErrors)
                    {
                        sb.AppendFormat("- {0} : {1}", error.PropertyName, error.ErrorMessage);
                        sb.AppendLine();
                    }
                }

                throw new DbEntityValidationException("Entity Validation Failed - errors follow:\n" + sb, ex); // Add the original exception as the innerException
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

private void SetAudit()
        {
            var addedAuditedEntities = ChangeTracker.Entries<EntityBase>().Where(p => p.State == EntityState.Added)
                .Select(p => p.Entity);
            var modifiedAuditedEntities = ChangeTracker.Entries<EntityBase>().Where(p => p.State == EntityState.Modified)
                .Select(p => p.Entity);
            var now = DateTime.UtcNow;
            foreach (var added in addedAuditedEntities)
            {
                added.DateCreated = now;
                added.CreatedBy = OwinContextHelper.CurrentApplicationUser;
                added.DateUpdated = now;
                added.UpdatedBy = OwinContextHelper.CurrentApplicationUser;
            }

            foreach (var modified in modifiedAuditedEntities)
            {
                if (modified.DateCreated == DateTime.MinValue)
                    modified.DateCreated = now;
                if (string.IsNullOrEmpty(modified.CreatedBy))
                    modified.CreatedBy = OwinContextHelper.CurrentApplicationUser;
                modified.DateUpdated = now;
                modified.UpdatedBy = OwinContextHelper.CurrentApplicationUser;
            }
        }

我如何从迁移中排除我的审计字段，因为它是'RowVersion'可能会改变？

标签： c#.netentity-frameworkentity-framework-6entity-framework-migrations