Joining Entities in LINQ

To join a subquery (INNER JOIN table) in EF Core, you can use the Join method along with LINQ expressions. Below is a example code snippet:

var query = from order in context.Orders
            join orderItem in context.OrderItems
            on order.OrderId equals orderItem.OrderId
            where order.CustomerName == "John Doe"
            select new
            {
                order.OrderId,
                order.CustomerName,
                orderItem.ProductName,
                orderItem.Price
            };

The expression on order.OrderId equals orderItem.OrderId is used to specify the join condition between two tables/entities (Orders and OrderItems  based on their related columns OrderId.

Additional Reading at EF Core Inner Join (csharptutorial.net)