Mybatis之执行自定义SQL举例

本文说明如何使用Mybatis执行我自定义输入的SQL语句。

需要的mybaits文件包括：配置文件（mybatis-config-dao.xml 和 jdbc.properties）、接口文件（ISqlMapper.class）、xml文件 (sqlMapper.xml)、工具类（MybatisUtils.class）。

依赖包：

         <dependency>
             <groupId>org.mybatis</groupId>
             <artifactId>mybatis</artifactId>
             <version>3.4.6</version>
         </dependency>

         <dependency>
             <groupId>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>
             <version>5.1.47</version>
         </dependency>

mybatis配置文件：

mybatis-config-dao.xml

 <?xml version="1.0" encoding="UTF-8" ?>
 <!DOCTYPE configuration
         PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
         "http://mybatis.org/dtd/mybatis-3-config.dtd">
 <configuration>
     <!--从外部配置文件导入jdbc信息-->
     <properties resource="config/jdbc.properties"></properties>

     <environments default="development">
         <environment id="development">
             <transactionManager type="JDBC"/>
             <dataSource type="POOLED">
                 <property name="driver" value="${driver}"/>
                 <property name="url" value="${url}"/>
                 <property name="username" value="${username}"/>
                 <property name="password" value="${password}"/>
             </dataSource>
         </environment>
     </environments>

     <!--指定映射资源文件-->
     <mappers>
         <mapper resource="mapper/shelby/userMapper.xml"/>
         <mapper resource="mapper/shelby/sqlMapper.xml"/>
     </mappers>

 </configuration>

jdbc.properties

# jdbc连接信息
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://10.15.1.232:3306/maserati_x??zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8
username=root
password=

接口文件 ISqlMapper.class

 package testTraffic.mapper.shelby;

 import java.util.List;
 import java.util.Map;

 public interface ISqlMapper {

     Integer insert(String statement);

     Integer delete(String statement);

     Integer update(String statement);

     List<Map<String, Object>> selectList(String statement);

     String selectOne(String statement);
 }

sqlMapper.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

 <mapper namespace="testTraffic.mapper.shelby.ISqlMapper">
     <insert id="insert" parameterType="java.lang.String">
         ${value}
     </insert>

     <select id="selectList" parameterType="java.lang.String" resultType="java.util.HashMap" useCache="false">
         ${value}
     </select>

     <select id="selectOne" parameterType="java.lang.String" resultType="java.lang.String" useCache="false">
         ${value}
     </select>

     <delete id="delete" parameterType="java.lang.String">
         ${value}
     </delete>

     <update id="update" parameterType="java.lang.String">
         ${value}
     </update>

 </mapper>

测试代码：

 package testTraffic.testDemo;

 import org.apache.ibatis.session.SqlSession;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.junit.Test;
 import testTraffic.mapper.shelby.ISqlMapper;
 import testTraffic.mapper.shelby.UserMapper;
 import testTraffic.utils.MybatisUtils;

 import java.util.List;

 /**
  * @Auther:GongXingRui
  * @Date:2019/1/24
  * @Description:
  **/
 public class TestMybatisDemo {
     private static Logger logger = LogManager.getLogger(TestMybatisDemo.class);

     // 直接执行SQL语句
     @Test
     public void testMybatisSelectOne() {
         String sql = "select user_name from t_admin_user where id = 2";
         ISqlMapper sqlMapper = MybatisUtils.getMapper(ISqlMapper.class);
         String name = sqlMapper.selectOne(sql);
         logger.info(name);
     }

     // 多个查询
     @Test
     public void testMybatisSelectList() {
         String sql = "select user_name from t_admin_user";
         ISqlMapper sqlMapper = MybatisUtils.getMapper(ISqlMapper.class);
         List list = sqlMapper.selectList(sql);
         logger.info(list);
     }

     // 删除与插入
     @Test
     public void testMybatisDeleteInsert() {
         ISqlMapper sqlMapper = MybatisUtils.getMapper(ISqlMapper.class);

         String deleteSql = "delete from t_admin_user  WHERE user_name = 'testuser';";
         String insertSql = "insert into `t_admin_user` (`id`, `user_name`, `user_password`, `del_flag`, `create_time`, `update_time`) VALUES( null,'testuser','testuser123','0','2019-01-21 19:43:58','2019-01-22 19:44:03');";
         int n = sqlMapper.delete(deleteSql);
         logger.info("删除数据：" + n);
         n = sqlMapper.insert(insertSql);
         logger.info("插入数据：" + n);
 //        MybatisUtils.getSession().commit();
     }

 }

自己封装的Mybatis工具类（MybatisUtils.class）

 package testTraffic.utils;

 import org.apache.ibatis.io.Resources;
 import org.apache.ibatis.session.SqlSession;
 import org.apache.ibatis.session.SqlSessionFactory;
 import org.apache.ibatis.session.SqlSessionFactoryBuilder;

 import java.io.IOException;
 import java.io.InputStream;

 /**
  * @Description: 生成mybatis的session对象
  **/
 public class MybatisUtils {
     private static String resource = "config/mybatis-config-dao.xml";
     private static SqlSessionFactory sqlSessionFactory = null;
     private static SqlSession session = null;

     private static void init() {
         try {
             InputStream inputStream = Resources.getResourceAsStream(resource);
 //            创建工厂
             sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
 //            创建session对象
             session = sqlSessionFactory.openSession(true);
         } catch (IOException e) {
             e.printStackTrace();
         }
     }

     public static SqlSession getSession() {
         if (session == null) {
             init();
         }
         return session;
     }

     public static void close() {
         if (session != null) {
             session.close();
             session = null;
         }
     }

     public static <T> T getMapper(Class<T> tClass) {
         if (session == null) {
             init();
         }
         return session.getMapper(tClass);
     }

     public static void commit() {
         if (session != null) {
             session.commit();
         }
     }

 }