如何在RavenDB查询中对一组过滤器运算符进行分组?

时间:2013-05-15 11:26:56

标签: linq lucene ravendb

为了过滤RavenDB中的产品,我使用了产品过滤器的通用列表 - 以避免长时间的切换。

产品过滤器类看起来像:

public class ProductFilter
{
    public string FilterName { get; set; }
    public List<string> FilterValues { get; set; }

    public ProductFilter()
    {
        FilterValues = new List<string>();
    }
}

FilterName等于索引属性名称

我使用此索引查询产品:

public class CategoryProducts_Index : AbstractIndexCreationTask<Product, CategoryProducts_Index.ReduceResult>
{
    public class ReduceResult
    {
        public string Category { get; set; }
        public string Title { get; set; }
        public string Brand { get; set; }
        public decimal RegularPrice { get; set; }
    }

    public CategoryProducts_Index()
    {
        Map = products =>
              from p in products
              from c in p.Categories
              select new
              {
                  Category = c,
                  Title = p.Title,
                  Brand = p.Brand,
                  RegularPrice = p.RegularPrice
              };
    }
}

对于通过循环ProductFilter列表来过滤产品的通用解决方案,我想实现一个Lucene查询分组,如:

Category: parent_category AND  (Category: sub_category_1 OR Category: sub_category_2 OR ...etc) AND (Brand: brand1 OR Brand:brand2 OR ...etc)

使用正常的Linq查询我无法通过字符串名称检索索引属性,因此我尝试使用LuceneQuery执行此操作,如下所示:

public IDocumentQuery<Product> GetProductsBySelectedFilters(string category, List<ProductFilter> productFilters)
    {
        IDocumentQuery<Product> products;
        using (var session = DocumentStore.OpenSession())
        {
            products = session.Advanced.LuceneQuery<Product>("CategoryProducts/Index", isMapReduce: true)
                .WhereStartsWith("Category", category);

            foreach (var filter in productFilters)
            {
                products.UsingDefaultOperator(QueryOperator.And);
                foreach (var value in filter.FilterValues)
                {
                    products.WhereEquals(filter.FilterName, value);
                    products.UsingDefaultOperator(QueryOperator.Or);
                }
            }
        }
        return products;
    }

Lucene输出查询,如:

Category: parent_category Category: sub_category_1 Category: sub_category_2 Brand: brand1  Brand: brand2  ...etc

这不是我的预期

有人知道如何处理这个问题吗?

1 个答案:

答案 0 :(得分:1)

使用LuceneQuery的.OpenSubclause()和.CloseSubclause()