如何向 Entity Framework 查询添加 where 子句

How to add a where clause to Entity Framework query

我一直在想办法给它添加一个 Where 子句。我需要

Where OrderHeader.OrderStatus = "NEW"

非常感谢任何帮助。

using (context)
{
    var orderData = context.OrderHeaders
                           .Join(context.OrderLines,
                                 OrderHeader => OrderHeader.Id,
                                 OrderLine => OrderLine.OrderHeaderId,
                                 (OrderHeader, OrderLine) => new
                                               {
                                                   Id = OrderHeader.Id
                                               }).ToList()

    foreach (var order in orderData)
    {
        CreateOrder(order.Id, context);
    }
}
context.OrderHeaders
    .Where(o => o.OrderStatus == "NEW")
    .Join(...