Question

So I am using EF, I have the following entities:

• Website
• Sector
• Product
• Attribute
• AttributeTag

The relationships are as follow:

I need to retrieve something that is not directly linked to the table. Such as products which needs a Sector object in order to retrieve only the specific Products using something such as sector.Products.

But what if I need to retrieve all Products under a given Website instead of it’s parent Sector ?

In my specific situation, my questions are:
1) How can I retrieve all the products given a specific website_id – (Disregarding the sector)
2) How can I retrieve all the products that have a specific tag_id + website_id. (Also retrieve it’s corresponding Attribute)

Help is appreciated. Thanks!

Answer 1

Assuming you’ve got both side navigation properties :

you will have a List<Sector> SectorList in Product Entity.

you will have a List<Product> ProductList in Sector Entity.

(sectors_products won’t be present as an entity, as it’s not needed in an object world).

you will have a Website Website in Sector Entity

you will have a List<AttributeTag> AttributeTagList in Product Entity;

(products_tags won’t be present as an entity, as it’s not needed in an object world).

1) something like :

var result = ProductEntities
             .Where(p => p.SectorList
                         .Any(s => s.WebSite.Id == <your_website_id>)
                    );

2) something like (taking 1) as base query)

result = result
         .Where(p => p.AttributeTagList
                     .Any(at => at.Id == <your_tag_id>)
               );

or all in one

var result = ProductEntitites
              .Where(p => 
                        p.SectorList.Any(s => s.WebSite.Id == <your_website_id>) &&
                        p.AttributeTagList.Any(at => at.Id == <your_tag_id>)
                     );