c# - 如何在 Entity Framework 6 中包含所有关系？

Question

Items = new ObservableCollection<CompanyContact>(
                        db.CompanyContacts
                        .Include(p => p.Facility)
                        .Include(p => p.Company)
                        .Include(p => p.Manager)
                        .OrderBy(s => s.Name)
                        .ToList<CompanyContact>()
                    );

有没有更优雅的写法？ 我想将每个关系都包含在一个表中。像 IncludeAll 这样的东西？ 谢谢!

Answer 1

EF 没有包含所有导航属性的方法。如果您需要预先加载所有这些，您别无选择，只能为要加载的每个导航属性调用所有包含。一个稍微更优雅的解决方案可能是使用这些扩展方法之一:

public static class IQueryableExtensions
{
    public static IQueryable<TEntity> GetAllIncluding<TEntity>(this IQueryable<TEntity> queryable, params string[] includeProperties)
    {
        return includeProperties.Aggregate(queryable, (current, includeProperty) => current.Include(includeProperty));
    }

    public static IQueryable<TEntity> GetAllIncludingWithFunc<TEntity>(this IQueryable<TEntity> queryable, params Expression<Func<TEntity, object>>[] includeProperties)
    {
        return includeProperties.Aggregate(queryable, (current, includeProperty) => current.Include(includeProperty));
    }
}

例如，使用第一种方法，您的查询将是这样的:

db.CompanyContacts.GetAllIncluding("Facility","Company", "Manager").OrderBy(s => s.Name).ToList();