How to use conditional aggregation sql query in Entity Framework?

Question

I am using Asp.Net MVC 5 and Entity Framework 6.2.0 with LINQ Extension Methods syntax.

I have 5 tables of variants, details below:

Product Table:

Answer 1

Try like this;

        var query = from s in YourDbContext.DbSet<ProductSKU>
            join voc in YourDbContext.DbSet<ProductVariantOptionCombination> on s.SkuID equals voc.SkuID
            join vo in YourDbContext.DbSet<ProductVariantOption> on voc.VariantOptionID equals vo.VariantOptionID
            join v in YourDbContext.DbSet<ProductVariant> on vo.VariantID equals v.VariantID
            group new {s,voc, vo, v} by s.Price
            into g
            select new
            {
                Price = g.Key,
                Size = g.Max(x => x.v.Name == "Size" ? x.vo.VariantOptionName : ""),
                Color = g.Max(x => x.v.Name == "Color" ? x.vo.VariantOptionName : ""),
                Material = g.Max(x => x.v.Name == "Material" ? x.vo.VariantOptionName : "")
            };