使用EF Core从多个到多个获取特定列

// 定义实体类
public class Order
{
    public int Id { get; set; }
    public string OrderNumber { get; set; }
    // 其他属性...
}

public class Product
{
    public int Id { get; set; }
    public string Name { get; set; }
    // 其他属性...
}

// 创建数据库上下文
public class MyDbContext : DbContext
{
    public DbSet<Order> Orders { get; set; }
    public DbSet<Product> Products { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer("连接字符串");
    }
}

// 查询数据
public List<string> GetOrderNumbersWithProductNames()
{
    using (var context = new MyDbContext())
    {
        var query = from order in context.Orders
                    join product in context.Products on order.Id equals product.Id
                    select new { order.OrderNumber, product.Name };

        return query.ToList().Select(x => $"{x.OrderNumber} - {x.Name}").ToList();
    }
}