使用Entity Framework从SQL数据库中获取所有内容

I have a list of Products like this

我有这样的产品清单

var r = db.Products.Where(x => x.Sites
                                .Where(z => z.Key == associatedProducts.Key)
                                .Any()
                  ).ToList()

There is an entity called Products, I want to get all elements from products except those exist in associatedProducts.Products

有一个名为Products的实体，我想从产品中获取所有元素，但那些存在于associatedProducts.Products中

How can i do that ?

我怎样才能做到这一点？

3 个解决方案

#1

The following query works if associatedProducts list is fetched using EF in a previos query.

如果在previos查询中使用EF获取associatedProducts列表，则以下查询有效。

var temp = db.Products.ToList().Except(associatedProducts).ToList();

otherwise, if associatedProducts is a list which has not been fetched using EF (assuming Key is an integer);

否则，如果associatedProducts是一个尚未使用EF获取的列表（假设Key是一个整数）;

List<int> tempIdList = associatedProducts.Select(q => q.Key ).ToList();
var temp = db.Products.Where(q => !tempIdList.Contains(q.Key));

#2

            var query = from p in db.Products
                        where !(from a in associatedProducts.Products
                                select a.Products)
                                .Contains(p.Key)
                        select p;

I didn't test the query, but it should look like this.

我没有测试查询，但它应该是这样的。

You should have a look at how you can use "not in" in linq:
How would you do a "not in" query with LINQ?

您应该看看如何在linq中使用“not in”：如何使用LINQ进行“不在”查询？

#3

-3

You can load the list of products that you want to exclude, and then .Exclude() it from the list of all products.

您可以加载要排除的产品列表，然后从所有产品列表中排除（）它。

#1