.net core dapper (3)

0.0 今天我又来了

　　问题解决与不解决他总是在那里.

 1. 调整一下我的表结构,然后然后做一个one to manny 的查询

 public class Order
    {
        public Guid OrderId { get; set; }
        public string OrderCode { get; set; }
        public string Address { get; set; }
        public string UserName { get; set; }
        public decimal TotalPrice { get; set; }
    }

public class OrderDetail
    {
        public Guid OrderDetailId { get; set; }
        public string ProductName { get; set; }
        public string Count { get; set; }
        public decimal Prcie { get; set; }
    }

2.数据库的结构

USE [Demo]
GO
/****** Object:  Table [dbo].[Order]    Script Date: 2019/11/27 22:47:26 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Order](
    [OrderId] [uniqueidentifier] NOT NULL,
    [OrderCode] [nvarchar](50) NULL,
    [Address] [nvarchar](100) NULL,
    [UserName] [nvarchar](50) NULL,
    [TotalPrice] [decimal](18, 2) NULL,
 CONSTRAINT [PK_Order] PRIMARY KEY CLUSTERED 
(
    [OrderId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[OrderDetail]    Script Date: 2019/11/27 22:47:26 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[OrderDetail](
    [OrderDetailId] [uniqueidentifier] NOT NULL,
    [OrderId] [uniqueidentifier] NULL,
    [ProductName] [nvarchar](100) NULL,
    [Count] [int] NULL,
    [Prcie] [decimal](18, 2) NULL,
 CONSTRAINT [PK_OrderDetail] PRIMARY KEY CLUSTERED 
(
    [OrderDetailId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
INSERT [dbo].[Order] ([OrderId], [OrderCode], [Address], [UserName], [TotalPrice]) VALUES (N'627be471-252b-4ff1-be57-732ac063035a', N'0002', N'河北', N'李四', CAST(47.21 AS Decimal(18, 2)))
GO
INSERT [dbo].[Order] ([OrderId], [OrderCode], [Address], [UserName], [TotalPrice]) VALUES (N'50c2cd9a-191b-491f-ae1f-964b2ac345ea', N'0001', N'北京', N'张三', CAST(33.21 AS Decimal(18, 2)))
GO
INSERT [dbo].[OrderDetail] ([OrderDetailId], [OrderId], [ProductName], [Count], [Prcie]) VALUES (N'60a771ea-7f2d-4101-990d-72554b3dc3e2', N'627be471-252b-4ff1-be57-732ac063035a', N'iphone', 1, CAST(2.30 AS Decimal(18, 2)))
GO
INSERT [dbo].[OrderDetail] ([OrderDetailId], [OrderId], [ProductName], [Count], [Prcie]) VALUES (N'032a1e95-3903-4bc2-9629-af12a71a58b9', N'627be471-252b-4ff1-be57-732ac063035a', N'笔记本', 1, CAST(4.30 AS Decimal(18, 2)))
GO

3.代码

 //4.one to many
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                string sql = "select * from [dbo].[Order] where orderid=@OrderId;select * from [dbo].[OrderDetail] where OrderId = @OrderId;";
                connection.Open();
                using (var multi = connection.QueryMultiple(sql, new { OrderId = "627BE471-252B-4FF1-BE57-732AC063035A" }))
                {
                    var order = multi.Read<Order>().First();
                    var orderDetail = multi.Read<OrderDetail>().ToList();
                }
            }

最简单的这一部分就到这儿了,接着下来我会结合 dapper 的扩张库 将dapper 封装为一个 Helper