使用轻量级ORM Dapper进行增删改查

下面的链接是Dapper 在github的地址  https://github.com/StackExchange/dapper-dot-net。

  使用 Dapper 进行简单增删改查示例

   1、首先根据数据库表定义实体对象， 这个工作完全可以使用T4、Nvelocity或者RazorEngine 写一个代码生成器根据数据库表对象自动生成数据库表实体对象。这里我自己根据表写了一个对象

  

 1    [Table("UserRole")]
 2    public class UserRoleDbEntity:DbEntityModelBase
 3     {
 4         [Description("用户编号，来自用户表")]
 5         public int UserId
 6         {
 7             get;
 8             set;
 9         }
10 
11        [Description("角色编号，来自于角色表")]
12         public int RoleId
13         {
14             get;
15             set;
16         }
17         /// 

18         /// 备注：AuthorityEnum.AuthorityValue 的取值范围是根据 AuthorityEnum位运算 或 与 的结果集；不可随意赋值
19         /// 
20         [Description("权限值")]
21         public int AuthorityValue { get; set; }
22 
23         /// 

24         /// 根据 AuthorityEnum 枚举值生成的描述
25         /// 
26         [Description("权限描述")]
27         public string AuthorityDescription { get; set; }
28     }
29 
30     /// 

31     /// 所有DbEntityModel项目中的实体必须继承DbEntityModelBase或其子类，使用supperType模式控制共有子类的行为或者状态，此项目中的类根据数据库基本表或者视图保持基本一致
32     /// 
33    public abstract class DbEntityModelBase
34     {
35         [Description("Guid标识")]
36         public string GuidMark
37         {
38             get;
39             set;
40         }
41         [Description("自增Id列")]
42         public int Id
43         {
44             get;
45             set;
46         }
47        [Description("排序，倒序")]
48         public int Sort
49         {
50             get;
51             set;
52         }
53     }

  2. 在DAL层就可以使用实体对象传参 或者作为返回值

 

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Linq;
  4 using System.Text;
  5 using OnlineExercise.DbAccess;
  6 using Dapper;
  7 using System.Configuration;
  8 using System.Data;
  9 using MySql.Data;
 10 using MySql.Data.MySqlClient;
 11 using OnlineExercise.DbEntityModel;
 12 using OnlineExercise.Log;
 13 using OnlineExercise.Infrastructrue;
 14 
 15 namespace OnlineExercise.DbAccess.SysAdminModule
 16 {
 17     public class UserRoleDB:DalBase
 18     {
 19         public int AddUserRole(UserRoleDbEntity model)
 20         {
 21             int affecgtRow = 0;
 22             string sql = @"INSERT INTO  `userrole`
 23                                     (`GuidMark`,
 24                                      `UserId`,
 25                                      `RoleId`,
 26                                      `AuthorityValue`,
 27                                      `AuthorityDescription`)
 28                         VALUES (@GuidMark,
 29                                 @UserId,
 30                                 @RoleId,
 31                                 @AuthorityValue,
 32                                 @AuthorityDescription);";
 33             using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
 34             {
 35                 affecgtRow = conn.Execute(sql, model);
 36             }
 37             return affecgtRow;
 38         }
 39 
 40         public int UpdateUserRoleByRoleIdAndUserId(UserRoleDbEntity model)
 41         {
 42             int affecgtRow = 0;
 43             string sql = @"UPDATE  `userrole`
 44                             SET  `AuthorityValue` = @AuthorityValue,
 45                                 `AuthorityDescription` = @AuthorityDescription
 46                             WHERE `UserId` = @UserId
 47                                 AND `RoleId` = @RoleId;";
 48             using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
 49             {
 50                 affecgtRow = conn.Execute(sql, model);
 51             }
 52             return affecgtRow;
 53         }
 54 
 55         public int UpdateUserRoleByRoleId(UserRoleDbEntity model)
 56         {
 57             int affecgtRow = 0;
 58             string sql = @"UPDATE  `userrole`
 59                             SET  `AuthorityValue` = @AuthorityValue,
 60                                 `AuthorityDescription` = @AuthorityDescription
 61                             WHERE `RoleId` = @RoleId;";
 62             using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
 63             {
 64                 affecgtRow = conn.Execute(sql, model);
 65             }
 66             return affecgtRow;
 67         }
 68 
 69         public int UpdateUserRoleByUserId(UserRoleDbEntity model)
 70         {
 71             int affecgtRow = 0;
 72             string sql = @"UPDATE  `userrole`
 73                             SET  `AuthorityValue` = @AuthorityValue,
 74                                 `AuthorityDescription` = @AuthorityDescription
 75                             WHERE `UserId` = @UserId;";
 76             using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
 77             {
 78                 affecgtRow = conn.Execute(sql, model);
 79             }
 80             return affecgtRow;
 81         }
 82 
 83         public List GetUserRoleListByRoleId(UserRoleDbEntity model)
 84         {
 85             List modelList = null;
 86             string sql = @"SELECT
 87                               `Id`,
 88                               `GuidMark`,
 89                               `sort`,
 90                               `UserId`,
 91                               `RoleId`,
 92                               `AuthorityValue`,
 93                               `AuthorityDescription`
 94                             FROM `userrole`
 95                             WHERE RoleId=@RoleId;";
 96             using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
 97             {
 98                 modelList = conn.Query(sql, model).ToList();
 99             }
100             return modelList;
101         }
102 
103 
104         public List GetUserRoleListByUserId(string userId)
105         {
106             List modelList = null;
107             string sql = @"SELECT
108                               `Id`,
109                               `GuidMark`,
110                               `sort`,
111                               `UserId`,
112                               `RoleId`,
113                               `AuthorityValue`,
114                               `AuthorityDescription`
115                             FROM `userrole`
116                             WHERE UserId=@UserId;";
117             using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
118             {
119                 modelList = conn.Query(sql, new { UserId =userId}).ToList();
120             }
121             return modelList;
122         }
123 
124         public List GetUserRoleListByRoleIdAndUserId(UserRoleDbEntity model)
125         {
126             List modelList = null;
127             string sql = @"SELECT
128                               `Id`,
129                               `GuidMark`,
130                               `sort`,
131                               `UserId`,
132                               `RoleId`,
133                               `AuthorityValue`,
134                               `AuthorityDescription`
135                             FROM `userrole`
136                             WHERE RoleId=@RoleId and UserId=@UserId;";
137             using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
138             {
139                 modelList = conn.Query(sql, model).ToList();
140             }
141             return modelList;
142         }
143 
144         public int DeleteUserRoleByUserId(string userId)
145         {
146             int affecgtRow = 0;
147             string sql = @"DELETE
148                             FROM  `userrole`
149                             WHERE `UserId` = @UserId";
150             using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
151             {
152                 affecgtRow = conn.Execute(sql, new { UserId = userId });
153             }
154             return affecgtRow;
155         }
156 
157         public int DeleteUserRoleByRoleId(string roleId)
158         {
159             int affecgtRow = 0;
160             string sql = @"DELETE
161                             FROM  `userrole`
162                             WHERE `RoleId` = @RoleId;";
163             using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
164             {
165                 affecgtRow = conn.Execute(sql, new { RoleId = roleId });
166                  
167             }
168             return affecgtRow;
169         }
170 
171         public DataTable GetRoleInfoByUserId(string userId)
172         {
173             DataTable dt = null;
174 
175             string sql = @"SELECT b.*,a.userid,c.name as userName  FROM userrole AS a
176                                 INNER JOIN role AS b ON a.roleid=b.id
177                                 INNER JOIN USER AS c ON c.id=a.userid
178                                 WHERE a.userid=@userid;";
179             using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
180             {
181                 IDataReader reader = conn.ExecuteReader(sql, new { userid=userId });
182                 dt = CoreUtil.DataReader2Table(reader);
183                 reader.Dispose();
184             }
185 
186             return dt;
187         }
188 
189     }
190 }

   Dapper的优势

 1、Dapper是一个轻型的ORM类

2、 Dapper语法简单，如果你喜欢写原始的sql，你一定喜欢Dapper。同时团队人员也很容易上手

3、Dapper 速度快，速度接近ADO.NET访问数据库的效率。

4、多数据库切换方便

    public int UpdateUserRoleByRoleId(UserRoleDbEntity model)
        {
            int affecgtRow = 0;
            string sql = @"UPDATE  `userrole`
                            SET  `AuthorityValue` = @AuthorityValue,
                                `AuthorityDescription` = @AuthorityDescription
                            WHERE `RoleId` = @RoleId;";
            using (IDbConnection conn = new MySqlConnection(GlobalVariablesManager.G_Strconn))
            {
                affecgtRow = conn.Execute(sql, model);
            }
            return affecgtRow;
        }

这里mysql如果要切换为Sql Server ，只要修改链接  MySqlConnection---》SqlConnection。

 

Dapper更多特性

1、支持动态dynamic绑定

 1 var rows = connection.Query("select 1 A, 2 B union all select 3, 4");
 2 
 3 ((int)rows[0].A)
 4    .IsEqualTo(1);
 5 
 6 ((int)rows[0].B)
 7    .IsEqualTo(2);
 8 
 9 ((int)rows[1].A)
10    .IsEqualTo(3);
11 
12 ((int)rows[1].B)
13     .IsEqualTo(4);

 

2、支持批量插入

1 connection.Execute(@"insert MyTable(colA, colB) values (@a, @b)",
2     new[] { new { a=1, b=1 }, new { a=2, b=2 }, new { a=3, b=3 } }
3   ).IsEqualTo(3); // 3 rows inserted: "1,1", "2,2" and "3,3"

3、支持多表关联

 1 var sql = 
 2 @"select * from #Posts p 
 3 left join #Users u on u.Id = p.OwnerId 
 4 Order by p.Id";
 5 
 6 var data = connection.Query(sql, (post, user) => { post.Owner = user; return post;});
 7 var post = data.First();
 8 
 9 post.Content.IsEqualTo("Sams Post1");
10 post.Id.IsEqualTo(1);
11 post.Owner.Name.IsEqualTo("Sam");
12 post.Owner.Id.IsEqualTo(99);

4、支持多结果查询

 1 var sql = 
 2 @"
 3 select * from Customers where CustomerId = @id
 4 select * from Orders where CustomerId = @id
 5 select * from Returns where CustomerId = @id";
 6 
 7 using (var multi = connection.QueryMultiple(sql, new {id=selectedId}))
 8 {
 9    var customer = multi.Read().Single();
10    var orders = multi.Read().ToList();
11    var returns = multi.Read().ToList();
12    ...
13 } 

5 支持存储过程

 1 var user = cnn.Query("spGetUser", new {Id = 1}, 
 2         commandType: CommandType.StoredProcedure).SingleOrDefault();
 3 // 你还可以获取存储过程out参数的输出值或者返回值
 4 var p = new DynamicParameters();
 5 p.Add("@a", 11);
 6 p.Add("@b", dbType: DbType.Int32, direction: ParameterDirection.Output);
 7 p.Add("@c", dbType: DbType.Int32, direction: ParameterDirection.ReturnValue);
 8 
 9 cnn.Execute("spMagicProc", p, commandType: CommandType.StoredProcedure); 
10 
11 int b = p.Get<int>("@b");
12 int c = p.Get<int>("@c"); 

6、参数自动绑定

1 new {A = 1, B = "b"} // A will be mapped to the param @A, B to the param @B 

  
 看到Dapper那么特性，觉得使用Dapper非常方便，使用也非常方便，扩展性也非常高。 当我用Dapper写一个demo给项目经理看的时候，项目经理就同意使用
Dapper 作为ORM 进行数据访问层的开发。从此就爱上了Dapper。
 希望这篇文章给你带来对Dapper清晰的了解。同时如果这文章给你到来了帮助，也别忘了帮忙推荐。