Mybatis.NET入门学习

本是古典何须时尚 2021-07-04 19:18 480阅读 0赞

MyBatis是一个数据映射工具。

它将包括存储过程的数据库查询的列映射到业务对象的属性。

映射器的一个定义是“在两个独立对象之间建立通信的对象。

数据映射器是“映射器层，用于在对象和数据库之间移动数据，同时使它们彼此之间以及映射器本身保持独立。

# 为什么？ #

.NET platform already provides a capable library for accessing databases, whether through SQL statements or stored procedures but several things are still hard to do well when using ADO.NET, including:  
`.NET`平台已经提供了一种功能强大的库，无论是通过SQL语句还是存储过程来访问数据库，但是使用`ADO.NET`时，仍然很难完成很多事情，包括：

*  将SQL代码与编程代码分开
 *  将输入参数传递给库类并提取输出
 *  将数据访问类与业务逻辑类分开
 *  缓存常用数据，直到数据更改
 *  管理事务和线程

`iBATIS DataMapper`通过使用`XML`文档在普通对象与`SQL`语句或存储过程之间创建映射来解决这些问题以及更多问题。

“普通对象”可以是`IDictionary`对象或属性对象。

# Hello World #

本文使用 Mysql 进行测试。如果是 SQL server 请直接参考本文最后的一系列文章。你可以在[这里][Link 1]查看完整代码。

先来看一下项目文件结构

.
    ├── ./mybatisNet
    │   ├── ./mybatisNet/Program.cs
    │   ├── ./mybatisNet/Properties
    │   │   └── ./mybatisNet/Properties/AssemblyInfo.cs
    │   ├── ./mybatisNet/Providers.config
    │   ├── ./mybatisNet/SqlMap.config
    │   ├── ./mybatisNet/app.config
    │   ├── ./mybatisNet/bin
    │   │   └── ./mybatisNet/bin/Debug
    │   │       └── ./mybatisNet/bin/Debug/mappers
    │   ├── ./mybatisNet/domain
    │   │   └── ./mybatisNet/domain/Mybatis.cs
    │   ├── ./mybatisNet/mappers
    │   │   └── ./mybatisNet/mappers/Mybatis.xml
    │   ├── ./mybatisNet/mybatisNet.csproj
    │   ├── ./mybatisNet/obj
    │   │   └── ./mybatisNet/obj/x86
    │   │       └── ./mybatisNet/obj/x86/Debug
    │   ├── ./mybatisNet/packages.config
    │   └── ./mybatisNet/service
    │       └── ./mybatisNet/service/MybatisService.cs
    ├── ./mybatisNet.sln
    ├── ./mybatisNet.userprefs
    └── ./packages
        ├── ./packages/MyBatis.NET.1.6.4
        │   ├── ./packages/MyBatis.NET.1.6.4/MyBatis.NET.1.6.4.nupkg
        │   └── ./packages/MyBatis.NET.1.6.4/lib
        │       ├── ./packages/MyBatis.NET.1.6.4/lib/IBatisNet.Common.dll
        │       ├── ./packages/MyBatis.NET.1.6.4/lib/IBatisNet.Common.pdb
        │       ├── ./packages/MyBatis.NET.1.6.4/lib/IBatisNet.Common.xml
        │       ├── ./packages/MyBatis.NET.1.6.4/lib/IBatisNet.DataMapper.dll
        │       ├── ./packages/MyBatis.NET.1.6.4/lib/IBatisNet.DataMapper.pdb
        │       └── ./packages/MyBatis.NET.1.6.4/lib/IBatisNet.DataMapper.xml
        └── ./packages/MySql.Data.6.9.9
            ├── ./packages/MySql.Data.6.9.9/CHANGES
            ├── ./packages/MySql.Data.6.9.9/MySql.Data.6.9.9.nupkg
            ├── ./packages/MySql.Data.6.9.9/Readme.txt
            ├── ./packages/MySql.Data.6.9.9/content
            │   ├── ./packages/MySql.Data.6.9.9/content/app.config.transform
            │   └── ./packages/MySql.Data.6.9.9/content/web.config.transform
            └── ./packages/MySql.Data.6.9.9/lib
                ├── ./packages/MySql.Data.6.9.9/lib/net40
                │   └── ./packages/MySql.Data.6.9.9/lib/net40/MySql.Data.dll
                └── ./packages/MySql.Data.6.9.9/lib/net45
                    └── ./packages/MySql.Data.6.9.9/lib/net45/MySql.Data.dll

零、准备一张表用来测试。

*  mybatis

CREATE TABLE `mybatis` (
      `id` bigint(20) NOT NULL AUTO_INCREMENT,
      `name` varchar(64) NOT NULL COMMENT '名称',
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB COMMENT='mybatis测试表';

### 一、引入对应的 DLL ###

1、 引入 `Mybatis.NET`

直接NUGET搜索【mybatis】安装即可。当前版本信息为 **1.6.4**.

2、 引入 `System.Data` 和 `Mysql.Data`

### 二、指定配置文件 ###

在c\#中 要将 `provider.config`、`sqlmap.config` 的属性设置为始终上传和内容，将`xxx.xml`设置为 始终上传和嵌入的资源。

换言之，比如保证编译后的文件里包含这些文件。

MONO里，文件上右键->【生成操作】->【`EmbeddedResource`】; 文件上右键->【快捷属性】->【复制到输出目录】.

1、数据映射器工作所需的第一件事是数据映射定义文件（`SqlMap.config`）。

*  `SqlMap.config`

<?xml version="1.0" encoding="utf-8"?>
    <sqlMapConfig xmlns="http://ibatis.apache.org/dataMapper" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    
      
      
      
      <settings>
        <setting useStatementNamespaces="false" />
        <setting cacheModelsEnabled="true" />
      </settings>
    
      
      <providers resource="Providers.config"/>
    
    
      <database>
        <provider name="MySql" />
        <dataSource name="MySql" connectionString="Host=127.0.0.1;UserName=root;Password=123456;Database=blog;Port=3306;CharSet=utf8;Allow Zero Datetime=true"/>
      </database>
    
      
      <sqlMaps>
    		<sqlMap resource="mappers/Mybatis.xml"/>
      </sqlMaps>
    
    </sqlMapConfig>

*  Providers.config

<?xml version="1.0" encoding="utf-8"?>
    <providers xmlns="http://ibatis.apache.org/providers" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
      <clear/>
    
    	<provider name="MySql" description="MySQL, MySQL provider V6.9.9.0" enabled="true" assemblyName="MySql.Data, Version=6.9.9.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" connectionClass="MySql.Data.MySqlClient.MySqlConnection" commandClass="MySql.Data.MySqlClient.MySqlCommand" parameterClass="MySql.Data.MySqlClient.MySqlParameter" parameterDbTypeClass="MySql.Data.MySqlClient.MySqlDbType" parameterDbTypeProperty="MySqlDbType" dataAdapterClass="MySql.Data.MySqlClient.MySqlDataAdapter" commandBuilderClass="MySql.Data.MySqlClient.MySqlCommandBuilder" usePositionalParameters="false" useParameterPrefixInSql="true" useParameterPrefixInParameter="true" parameterPrefix="@" allowMARS="false" />
    </providers>

*  Mybatis.xml & Mybatis.cs

<?xml version="1.0" encoding="utf-8" ?>
    <sqlMap namespace="mybatisNet.mappers" xmlns="http://ibatis.apache.org/mapping" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    
      <resultMaps>
        <resultMap id="BaseResultMap" class="mybatisNet.doamin.Mybatis">
    
    		<id property="id" column="id" dbType="BIGINT" />
          <result property="name" column="name" dbType="VARCHAR"/>
        </resultMap>
      </resultMaps>
    
      <statements>
    
    	<select id="QueryMybatis" resultMap="BaseResultMap" parameterClass="System.Int32">
    		SELECT id, name
    			FROM `mybatis` 
    			WHERE (id = #value#)
    	</select>	
    
        <insert id="InsertMybatis" parameterClass="mybatisNet.doamin.Mybatis">
          INSERT INTO `mybatis` (id, name) VALUES (
    		  #id#, #name#
    		);
        </insert>
    
    	<delete id="DeleteMybatis" parameterClass="mybatisNet.doamin.Mybatis">
          DELETE FROM `mybatis`
          WHERE
          (id = #id#)
        </delete>
    
    	<update id="UpdateMybatis" parameterClass="mybatisNet.doamin.Mybatis">
          UPDATE `mybatis` 
    	  SET
          name = #name#
          WHERE
          (id = #id#)
        </update>	
    
      </statements>
    </sqlMap>

using System;
    namespace mybatisNet.doamin
    { 
    	[Serializable]
    	public class Mybatis
    	{ 
    		/// <summary>
    		/// The identifier.
    		/// </summary>
    		private int id;
    		/// <summary>
    		/// The name.
    		/// </summary>
    		private string name;		
    		public int Id
    		{ 
    			get
    			{ 
    				return id;
    			}
    			set
    			{ 
    				id = value;
    			}
    		}
    		public string Name
    		{ 
    			get
    			{ 
    				return name;
    			}
    			set
    			{ 
    				name = value;
    			}
    		}
    		public override string ToString()
    		{ 
    			return string.Format("[Mybatis: id={0}, name={1}]", id, name);
    		}
    	}
    }

*  MybatisService.cs

using System;
    using IBatisNet.DataMapper;
    using IBatisNet.DataMapper.Configuration;
    using mybatisNet.doamin;
    namespace mybatisNet
    { 
    	public class MybatisService
    	{ 
    		/// <summary>
    		/// Inserts the mybatis.
    		/// </summary>
    		/// <param name="mybatis">Mybatis.</param>
    		public void InsertMybatis(Mybatis mybatis)
    		{ 
    			ISqlMapper mapper = EntityMapper;
    			try
    			{ 
    				mapper.Insert("InsertMybatis", mybatis);
    			}
    			catch (Exception ex)
    			{  
    				Console.WriteLine("ex when InsertMybatis:{0}", ex);
    			}
    		}
    		/// <summary>
    		/// Queries the mybatis.
    		/// </summary>
    		/// <returns>The mybatis.</returns>
    		/// <param name="id">Identifier.</param>
    		public Mybatis QueryMybatis(int id)
    		{  
    			ISqlMapper mapper = EntityMapper;
    			try
    			{ 
    				Mybatis result = mapper.QueryForObject<Mybatis>("QueryMybatis", id);
    				return result;
    			}
    			catch (Exception ex)
    			{ 
    				Console.WriteLine("ex:{0}", ex);
    				return null;
    			}
    		}
    		/// <summary>
    		/// Updates the mybatis.
    		/// </summary>
    		/// <returns>The mybatis.</returns>
    		/// <param name="mybatis">Mybatis.</param>
    		public int UpdateMybatis(Mybatis mybatis)
    		{ 
    			ISqlMapper mapper = EntityMapper;
    			try
    			{ 
    				int result = mapper.Update("UpdateMybatis", mybatis);
    				return result;
    			}
    			catch (Exception ex)
    			{ 
    				Console.WriteLine("ex:{0}", ex);
    				return 0;
    			}
    		}
    		public int DeleteMybatis(Mybatis mybatis)
    		{ 
    			ISqlMapper mapper = EntityMapper;
    			try
    			{ 
    				int result = mapper.Delete("DeleteMybatis", mybatis);
    				return result;
    			}
    			catch (Exception ex)
    			{ 
    				Console.WriteLine("ex:{0}", ex);
    				return 0;
    			}
    		}
    		/// <summary>
    		/// Gets the entity mapper.
    		/// </summary>
    		/// <value>The entity mapper.</value>
    		public static ISqlMapper EntityMapper
    		{ 
    			get
    			{ 
    				try
    				{ 
    					ISqlMapper mapper = Mapper.Instance();
    					return mapper;
    				}
    				catch (Exception ex)
    				{ 
    					Console.WriteLine("ex:{0}", ex);
    					//throw ex;
    					return null;
    				}
    			}
    		}
    	}
    }

*  Simple Test code

这里偷懒了。没有写对应的单元测试。都是简单的调用。

using System;
    using IBatisNet.DataMapper;
    using IBatisNet.DataMapper.Configuration;
    using mybatisNet.doamin;
    namespace mybatisNet
    { 
    	class MainClass
    	{ 
    		public static void Main(string[] args)
    		{ 
    			MybatisService service = new MybatisService();
    			//Mybatis mybatis = new Mybatis();
    			//mybatis.Id = 3;
    			//mybatis.Name = "hello mybatis .net update";
    			//service.InsertMybatis(mybatis);
    			//service.Q
    			//service.UpdateMybatis(mybatis);
    			//service.DeleteMybatis(mybatis);
    			Console.WriteLine("result: {0}", service.QueryMybatis(1));
    		}
    	}
    }

最后：

比较而言，C\# 版本的 mybatis 已经停止更新了。文档也不是很全。

如果你知道 java 版本的，肯定不会去手写这里的 model,mapper。C\# 可以借助[codesmithtools][]，Mac上安装不了，此刻跳过。

# 动态SQL #

也就是说，此时的`mybatisNet(V1.6.4.0)` 和 以前的 Java版本 `ibatis` 保持一致。==

> [IBatis.net动态SQL语句][IBatis.net_SQL]

# 打印SQL的LOG #

> [mybatisNet with log4net][]

# 神奇的BUG #

情景说明：

当涉及到2张表时：且二者的字段不完全相同。

当后者查询时，而且查询的是自己的表。就会莫名其妙的出现第一张的字段。(`name` 这个字段在 `mybatis`这张表中)报错如下：

（初步猜测，会将所有的 statement 执行一遍。）但是这个问题又是不可能出现的，因为这么多人用。不知道我什么地方配置出错了。

ex:System.IndexOutOfRangeException: Could not find specified column in results: name
      at MySql.Data.MySqlClient.ResultSet.GetOrdinal (System.String name) [0x0002f] in <0a135c8e4d604d948724bf6960583b7f>:0 
      at MySql.Data.MySqlClient.MySqlDataReader.GetOrdinal (System.String name) [0x00020] in <0a135c8e4d604d948724bf6960583b7f>:0 
      at IBatisNet.DataMapper.Commands.DataReaderDecorator.System.Data.IDataRecord.GetOrdinal (System.String name) [0x00000] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.TypeHandlers.StringTypeHandler.GetValueByName (IBatisNet.DataMapper.Configuration.ResultMapping.ResultProperty mapping, System.Data.IDataReader dataReader) [0x00007] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.Configuration.ResultMapping.ResultProperty.GetDataBaseValue (System.Data.IDataReader dataReader) [0x00015] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.MappedStatements.PropertyStrategy.DefaultStrategy.Get (IBatisNet.DataMapper.Scope.RequestScope request, IBatisNet.DataMapper.Configuration.ResultMapping.IResultMap resultMap, IBatisNet.DataMapper.Configuration.ResultMapping.ResultProperty mapping, System.Object& target, System.Data.IDataReader reader) [0x0008a] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.MappedStatements.PropertyStrategy.DefaultStrategy.Set (IBatisNet.DataMapper.Scope.RequestScope request, IBatisNet.DataMapper.Configuration.ResultMapping.IResultMap resultMap, IBatisNet.DataMapper.Configuration.ResultMapping.ResultProperty mapping, System.Object& target, System.Data.IDataReader reader, System.Object keys) [0x00000] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.MappedStatements.ResultStrategy.ResultMapStrategy.Process (IBatisNet.DataMapper.Scope.RequestScope request, System.Data.IDataReader& reader, System.Object resultObject) [0x0008f] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.MappedStatements.ResultStrategy.MapStrategy.Process (IBatisNet.DataMapper.Scope.RequestScope request, System.Data.IDataReader& reader, System.Object resultObject) [0x0002a] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.MappedStatements.MappedStatement.RunQueryForObject[T] (IBatisNet.DataMapper.Scope.RequestScope request, IBatisNet.DataMapper.ISqlMapSession session, System.Object parameterObject, T resultObject) [0x00013] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
    result: 
    Press any key to continue...

原因如下：

这里的 `resultMap.id` 也请务必保持唯一。

*  执行

Console.WriteLine("result: {0}", new MethodInfoDao().QueryMethodInfo(1));

*  查询方法如下

public MethodInfo QueryMethodInfo(int id)
    { 
        try
        { 
            ISqlMapper mapper = Mapper.Instance();
            MethodInfo result = mapper.QueryForObject<MethodInfo>("QueryMethodInfo", id);
            return result;
        }
        catch (Exception ex)
        { 
            Console.WriteLine("ex:{0}", ex);
            return null;
        }
    }

*  MethodInfo.xml

猜想的验证

*  配置 `log4net for mybatisNet`

修改 app.config

<?xml version="1.0" encoding="utf-8"?>
    <configuration>
    
      <configSections>
        <sectionGroup name="iBATIS">
          <section name="logging" type="IBatisNet.Common.Logging.ConfigurationSectionHandler, IBatisNet.Common" />
        </sectionGroup>
        <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
      </configSections>
    
       
      <iBATIS>
        <logging>
          <logFactoryAdapter type="IBatisNet.Common.Logging.Impl.ConsoleOutLoggerFA, IBatisNet.Common">
            <arg key="showLogName" value="true" />
            <arg key="showDataTime" value="true" />
            <arg key="level" value="ALL" />
            <arg key="dateTimeFormat" value="yyyy/MM/dd HH:mm:ss:SSS" />
          </logFactoryAdapter>
        </logging>
      </iBATIS>
    
    </configuration>

日志如下：

2017/04/12 22:33:38:SSS [DEBUG] IBatisNet.Common.Utilities.ConfigWatcherHandler - Adding file [SqlMap.config] to list of watched files.
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.Common.Utilities.ConfigWatcherHandler - Adding file [Mybatis.xml] to list of watched files.
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.DataMapper.Configuration.Statements.PreparedStatementFactory - Statement Id: [QueryMybatis] Prepared SQL: [SELECT id, name    FROM `mybatis`     WHERE (id =  @param0 )]
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.DataMapper.Configuration.Statements.PreparedStatementFactory - Statement Id: [InsertMybatis] Prepared SQL: [INSERT INTO `mybatis` (id, name) VALUES (      @param0 ,  @param1    );]
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.DataMapper.Configuration.Statements.PreparedStatementFactory - Statement Id: [UpdateMybatis] Prepared SQL: [UPDATE `mybatis`     SET       name =  @param0        WHERE       (id =  @param1 )]
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.DataMapper.Configuration.Statements.PreparedStatementFactory - Statement Id: [DeleteMybatis] Prepared SQL: [DELETE FROM `mybatis`       WHERE       (id =  @param0 )]
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.Common.Utilities.ConfigWatcherHandler - Adding file [MethodInfo.xml] to list of watched files.
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.DataMapper.Configuration.Statements.PreparedStatementFactory - Statement Id: [QueryMethodInfo] Prepared SQL: [SELECT id, methodName    FROM `methodInfo`     WHERE (id =  @param0 )]
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.DataMapper.Commands.DefaultPreparedCommand - Statement Id: [QueryMethodInfo] PreparedStatement : [SELECT id, methodName    FROM `methodInfo`     WHERE (id =  @param0 )]
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.DataMapper.Commands.DefaultPreparedCommand - Statement Id: [QueryMethodInfo] Parameters: [@param0=[value,1]]
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.DataMapper.Commands.DefaultPreparedCommand - Statement Id: [QueryMethodInfo] Types: [@param0=[Int32, System.Int32]]
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.DataMapper.SqlMapSession - Open Connection "21023919" to "MySQL, MySQL provider V6.9.9.0".
    2017/04/12 22:33:39:SSS [DEBUG] IBatisNet.DataMapper.SqlMapSession - Close Connection "21023919" to "MySQL, MySQL provider V6.9.9.0".
    ex:System.IndexOutOfRangeException: Could not find specified column in results: name
      at MySql.Data.MySqlClient.ResultSet.GetOrdinal (System.String name) [0x0002f] in <0a135c8e4d604d948724bf6960583b7f>:0 
      at MySql.Data.MySqlClient.MySqlDataReader.GetOrdinal (System.String name) [0x00020] in <0a135c8e4d604d948724bf6960583b7f>:0 
      at IBatisNet.DataMapper.Commands.DataReaderDecorator.System.Data.IDataRecord.GetOrdinal (System.String name) [0x00000] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.TypeHandlers.StringTypeHandler.GetValueByName (IBatisNet.DataMapper.Configuration.ResultMapping.ResultProperty mapping, System.Data.IDataReader dataReader) [0x00007] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.Configuration.ResultMapping.ResultProperty.GetDataBaseValue (System.Data.IDataReader dataReader) [0x00015] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.MappedStatements.PropertyStrategy.DefaultStrategy.Get (IBatisNet.DataMapper.Scope.RequestScope request, IBatisNet.DataMapper.Configuration.ResultMapping.IResultMap resultMap, IBatisNet.DataMapper.Configuration.ResultMapping.ResultProperty mapping, System.Object& target, System.Data.IDataReader reader) [0x0008a] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.MappedStatements.PropertyStrategy.DefaultStrategy.Set (IBatisNet.DataMapper.Scope.RequestScope request, IBatisNet.DataMapper.Configuration.ResultMapping.IResultMap resultMap, IBatisNet.DataMapper.Configuration.ResultMapping.ResultProperty mapping, System.Object& target, System.Data.IDataReader reader, System.Object keys) [0x00000] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.MappedStatements.ResultStrategy.ResultMapStrategy.Process (IBatisNet.DataMapper.Scope.RequestScope request, System.Data.IDataReader& reader, System.Object resultObject) [0x0008f] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.MappedStatements.ResultStrategy.MapStrategy.Process (IBatisNet.DataMapper.Scope.RequestScope request, System.Data.IDataReader& reader, System.Object resultObject) [0x0002a] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
      at IBatisNet.DataMapper.MappedStatements.MappedStatement.RunQueryForObject[T] (IBatisNet.DataMapper.Scope.RequestScope request, IBatisNet.DataMapper.ISqlMapSession session, System.Object parameterObject, T resultObject) [0x00013] in <ed90c8d30e2d4724a3bee124edf80dbd>:0 
    result:

本来我应该执行的只有一句 `[SELECT id, methodName FROM methodInfo WHERE (id = @param0 )]`， 可是前面另一张表的各种`SQL`也被预打印了一遍？？？

如果只是将查询改成这样

public MethodInfo QueryMethodInfo(int id)
    { 
     try
     { 
         ISqlMapper mapper = Mapper.Instance();
         //MethodInfo result = mapper.QueryForObject<MethodInfo>("QueryMethodInfo", id);
         //return result;
         return null;
     }
     catch (Exception ex)
     { 
         Console.WriteLine("ex:{0}", ex);
         return null;
     }
    }

LOG如下，且不会报错。

[Link 1]: https://github.com/houbb/mybatisNet.git
[codesmithtools]: http://www.codesmithtools.com/
[IBatis.net_SQL]: http://www.cnblogs.com/kissdodog/archive/2013/11/21/3436587.html
[mybatisNet with log4net]: http://www.cnblogs.com/Dunk/p/3714689.html