使用实体框架核心获取多个表

// 定义实体类
public class Order
{
    public int Id { get; set; }
    public string OrderNumber { get; set; }
    public int CustomerId { get; set; }
    public Customer Customer { get; set; }
}

public class Customer
{
    public int Id { get; set; }
    public string Name { get; set; }
}

// 配置数据上下文
public class MyDbContext : DbContext
{
    public DbSet<Order> Orders { get; set; }
    public DbSet<Customer> Customers { get; set; }

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

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Order>()
            .HasOne(o => o.Customer)
            .WithMany()
            .HasForeignKey(o => o.CustomerId);
    }
}

// 查询多个表
using (var context = new MyDbContext())
{
    var orders = context.Orders
        .Include(o => o.Customer)
        .ToList();

    foreach (var order in orders)
    {
        Console.WriteLine($"订单号：{order.OrderNumber}，客户名：{order.Customer.Name}");
    }
}