.net core dapper (3)

 

 1. 调整一下我的表结构,然后然后做一个one to manny 的查询

 1  public class Order
 2     {
 3         public Guid OrderId { get; set; }
 4         public string OrderCode { get; set; }
 5         public string Address { get; set; }
 6         public string UserName { get; set; }
 7         public decimal TotalPrice { get; set; }
 8     }
 9 
10 public class OrderDetail
11     {
12         public Guid OrderDetailId { get; set; }
13         public string ProductName { get; set; }
14         public string Count { get; set; }
15         public decimal Prcie { get; set; }
16     }

 

2.数据库的结构

 1 USE [Demo]
 2 GO
 3 /****** Object:  Table [dbo].[Order]    Script Date: 2019/11/27 22:47:26 ******/
 4 SET ANSI_NULLS ON
 5 GO
 6 SET QUOTED_IDENTIFIER ON
 7 GO
 8 CREATE TABLE [dbo].[Order](
 9     [OrderId] [uniqueidentifier] NOT NULL,
10     [OrderCode] [nvarchar](50) NULL,
11     [Address] [nvarchar](100) NULL,
12     [UserName] [nvarchar](50) NULL,
13     [TotalPrice] [decimal](18, 2) NULL,
14  CONSTRAINT [PK_Order] PRIMARY KEY CLUSTERED 
15 (
16     [OrderId] ASC
17 )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
18 ) ON [PRIMARY]
19 GO
20 /****** Object:  Table [dbo].[OrderDetail]    Script Date: 2019/11/27 22:47:26 ******/
21 SET ANSI_NULLS ON
22 GO
23 SET QUOTED_IDENTIFIER ON
24 GO
25 CREATE TABLE [dbo].[OrderDetail](
26     [OrderDetailId] [uniqueidentifier] NOT NULL,
27     [OrderId] [uniqueidentifier] NULL,
28     [ProductName] [nvarchar](100) NULL,
29     [Count] [int] NULL,
30     [Prcie] [decimal](18, 2) NULL,
31  CONSTRAINT [PK_OrderDetail] PRIMARY KEY CLUSTERED 
32 (
33     [OrderDetailId] ASC
34 )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
35 ) ON [PRIMARY]
36 GO
37 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)))
38 GO
39 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)))
40 GO
41 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)))
42 GO
43 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)))
44 GO

 

3.代码

 1  //4.one to many
 2             using (SqlConnection connection = new SqlConnection(connectionString))
 3             {
 4                 string sql = "select * from [dbo].[Order] where orderid=@OrderId;select * from [dbo].[OrderDetail] where OrderId = @OrderId;";
 5                 connection.Open();
 6                 using (var multi = connection.QueryMultiple(sql, new { OrderId = "627BE471-252B-4FF1-BE57-732AC063035A" }))
 7                 {
 8                     var order = multi.Read<Order>().First();
 9                     var orderDetail = multi.Read<OrderDetail>().ToList();
10                 }
11             }

 

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