实体框架通用存储库，包括通过参数的属性 [英] Entity Framework Generic repository including properties through parameter

问题描述

我在实体框架中有一个通用存储库的实现，我正在尝试改进它以使用 EF 提供的 .Include(..) 函数，而不是按字符串包含导航属性，以便能够安全地重命名属性.

I have an implementation of a Generic Repository in Entity Framework which I am trying to improve to use the .Include(..) function provided by EF instead of including the navigation properties by string, in order to be able to safely rename properties.

以下是我当前的代码:

public IQueryable<T> GetAll(
        Expression<Func<T, bool>> filter = null,
        Func<IQueryable<T>, IOrderedQueryable<T>> orderBy = null,
        string includeProperties = "")
    {
        IQueryable<T> query = dbSet;

        if (filter != null)
        {
            query = query.Where(filter);
        }

        foreach (var includeProperty in includeProperties.Split
            (new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries))
        {
            query = query.Include(includeProperty);
        }

        if (orderBy != null)
        {
            return orderBy(query);
        }
        else
        {
            return query;
        }
    }

我目前以下列方式使用它:

I currently use this in the following way:

repository.GetAll(
    u => u.Name = "John",
    u => u.OrderBy(x => x.Name),
    "Address.State",
);

我的问题是:如何更改方法以便能够以以下方式(或类似方式)调用它:

My question is: how can I change the method in order to be able to call it in the following way (or similar):

repository.GetAll(
    u => u.Name = "John",
    u => u.OrderBy(x => x.Name),
    u => u.Include(x => x.Address).ThenInclude(x => x.State),
);

推荐答案

protected internal IQueryable<TEntity> Filter(Expression<Func<TEntity, bool>> predicate, params Expression<Func<TEntity, object>>[] includeProperties)
{
    var query = RetrieveQuery();

    if (predicate != null)
    {
        query = query.Where(predicate).AsQueryable();
    }

    if (includeProperties != null)
    {
        query = _queryableUnitOfWork.ApplyIncludesOnQuery(query, includeProperties);
    }

    return (query);
}

这个方法在那里调用

public IQueryable<TEntity> ApplyIncludesOnQuery<TEntity>(IQueryable<TEntity> query, params Expression<Func<TEntity, object>>[] includeProperties) where TEntity : class, IEntity
{
    // Return Applied Includes query
    return (includeProperties.Aggregate(query, (current, include) => current.Include(include)));
}

过滤方法调用

 public IEnumerable<ShowStockProductDto> GetActiveShowStockProductListByProduct(int productId)
            {
                var foundedPStockroducts = Filter(
                    ent => ent.ProductId == productId && ent.IsActive,
                    ent => ent.StockProductPrices,
                    ent => ent.StockProductDepots,
                    ent => ent.StockProductSpecificationValues,
                    ent => ent.StockProductSpecificationValues.Select(spsv => spsv.SpecificationValue)
                    );

                // Map foundedPStockroducts to showStockProductList
                var showStockProductList = TypeAdapterFactory.Adapter.Adapt<IEnumerable<ShowStockProductDto>>(foundedPStockroducts).ToList();

                return (showStockProductList);
            }

这篇关于实体框架通用存储库，包括通过参数的属性的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！