Question
Simple question, but no luck with Google so far.
How do I turn this:
select * from Products
left join ProductCategory on Products.ProductCode = ProductCategory.ProductCode
where ProductCategory.CategoryID = 1
into a query in Entity Framework Core?
This is what I have and isn't correct:
_context.Products
.Where(p => p.ProductCategory.CategoryID == CategoryID)
.ToList();
Thanks!
Edit
When I add an Include:
_context.Products
.Include(p => p.ProductCategory)
.Where(p => p.ProductCategory.CategoryID == CategoryID)
.ToList();
I get this error in the image:
There is a CategoryID on ProductCategory, but it's trying to find one on the collection?
Accepted Answer
You should use the Include() LINQ option - documentation. It is used for loading related data.
I'm not familiar with the exact names of your classes and properties, so treat this as a pseudo code, but it should look something like this:
_context.products.Include("Product_Categories")
.Where(p => p.product_category.category_id == category_id)
EDIT
It will be a lot easier if you post your classes, so that I can see the relations.
But I assume that your Product class has a list of ProductCategory and you want to get all the products, that have a specific category. Extending the approach that you already have, you need:
_context.products
.Include(p => p.product_category)
.Where(p => p.ProductCategory.Any(pc => pc.category_id == category_id))
.ToList();
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