Question

我想基于实体类型创建一个存储库。任何想法如何做到这一点？

我们有很多实体，所以这需要是通用代码。
我们需要为我们拥有的每个实体提供历史记录表。
我们使用代码优先，DbContext，EF 5.0使用存储库和工作单元格式。

以下是我们必须在SaveChanges方法中进行更改的代码。对于每个已修改和已删除的实体，我们希望将旧行保存到历史记录表中。以下是单个实体的硬编码：ServiceLocation。

所有实体都有相应的历史实体。例如，对于ServiceLocation实体，有一个ServiceLocationHistory实体（和存储库）。

如果modifiedEntity的类型为ServiceLocation，我该如何创建ServiceLocationHistoryRepository？并使其适用于所有类型？

  public override int SaveChanges()
    {
        // Get the entities that changed
        var addedEntries = ChangeTracker.Entries().Where(e => e.State == EntityState.Added && e.Entity is IHistoryBase).Select(e => (TBaseEntity)e.Entity);
        var modifiedEntries = ChangeTracker.Entries().Where(e => e.State == EntityState.Modified && e.Entity is IHistoryBase).Select(e => (TBaseEntity)e.Entity);
        var deletedEntries = ChangeTracker.Entries().Where(e => e.State == EntityState.Deleted && e.Entity is IHistoryBase).Select(e => (TBaseEntity)e.Entity);

        // Debugging watch varibles
        int x = addedEntries.Count();
        int y = modifiedEntries.Count();
        int z = deletedEntries.Count();

        // Create the Type adapter
        TypeAdapter adapter = new TypeAdapter(new RegisterTypesMap[] { new HistoryRegisterTypesMap() });
        var serviceLocationHistoryRepository = new ServiceLocationHistoryRepository(this);

        foreach (var addedEntry in addedEntries)
        {
            addedEntry.FromDate = DateTime.Now;
            addedEntry.ToDate = DateTime.Parse("9999-12-31 00:00:00.0000000");
        }

        foreach (var modifiedEntry in modifiedEntries)
        {

            ServiceLocationHistory history = adapter.Adapt<ServiceLocation, ServiceLocationHistory>(modifiedEntry as ServiceLocation);
            serviceLocationHistoryRepository.Add(history);

            history.FromDate = modifiedEntry.FromDate;
            history.ToDate = modifiedEntry.FromDate = DateTime.Now;
            modifiedEntry.ToDate = DateTime.Parse("9999-12-31 00:00:00.0000000");
        }

        foreach (var deletedEntry in deletedEntries)
        {
            ServiceLocationHistory history = adapter.Adapt<ServiceLocation, ServiceLocationHistory>(deletedEntry as ServiceLocation);
            serviceLocationHistoryRepository.Add(history);

            history.FromDate = deletedEntry.FromDate;
            history.ToDate = DateTime.Now;
         }
        return base.SaveChanges();

    }

根据实体类型创建存储库

0 个答案: