Mybatis之执行自定义SQL举例

Posted 2021-02-05 星瑞的随笔

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：

 1         <dependency>
 2             <groupId>org.mybatis</groupId>
 3             <artifactId>mybatis</artifactId>
 4             <version>3.4.6</version>
 5         </dependency>
 6 
 7         <dependency>
 8             <groupId>mysql</groupId>
 9             <artifactId>mysql-connector-java</artifactId>
10             <version>5.1.47</version>
11         </dependency>

 

mybatis配置文件：

mybatis-config-dao.xml

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <!DOCTYPE configuration
 3         PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 4         "http://mybatis.org/dtd/mybatis-3-config.dtd">
 5 <configuration>
 6     <!--从外部配置文件导入jdbc信息-->
 7     <properties resource="config/jdbc.properties"></properties>
 8 
 9     <environments default="development">
10         <environment id="development">
11             <transactionManager type="JDBC"/>
12             <dataSource type="POOLED">
13                 <property name="driver" value="${driver}"/>
14                 <property name="url" value="${url}"/>
15                 <property name="username" value="${username}"/>
16                 <property name="password" value="${password}"/>
17             </dataSource>
18         </environment>
19     </environments>
20 
21     <!--指定映射资源文件-->
22     <mappers>
23         <mapper resource="mapper/shelby/userMapper.xml"/>
24         <mapper resource="mapper/shelby/sqlMapper.xml"/>
25     </mappers>
26 
27 </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

 1 package testTraffic.mapper.shelby;
 2 
 3 import java.util.List;
 4 import java.util.Map;
 5 
 6 public interface ISqlMapper {
 7 
 8     Integer insert(String statement);
 9 
10     Integer delete(String statement);
11 
12     Integer update(String statement);
13 
14     List<Map<String, Object>> selectList(String statement);
15 
16     String selectOne(String statement);
17 }

 

sqlMapper.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 3 
 4 <mapper namespace="testTraffic.mapper.shelby.ISqlMapper">
 5     <insert id="insert" parameterType="java.lang.String">
 6         ${value}
 7     </insert>
 8 
 9     <select id="selectList" parameterType="java.lang.String" resultType="java.util.HashMap" useCache="false">
10         ${value}
11     </select>
12 
13     <select id="selectOne" parameterType="java.lang.String" resultType="java.lang.String" useCache="false">
14         ${value}
15     </select>
16 
17     <delete id="delete" parameterType="java.lang.String">
18         ${value}
19     </delete>
20 
21     <update id="update" parameterType="java.lang.String">
22         ${value}
23     </update>
24 
25 </mapper>

 

测试代码：

 1 package testTraffic.testDemo;
 2 
 3 import org.apache.ibatis.session.SqlSession;
 4 import org.apache.logging.log4j.LogManager;
 5 import org.apache.logging.log4j.Logger;
 6 import org.junit.Test;
 7 import testTraffic.mapper.shelby.ISqlMapper;
 8 import testTraffic.mapper.shelby.UserMapper;
 9 import testTraffic.utils.MybatisUtils;
10 
11 import java.util.List;
12 
13 /**
14  * @Auther:GongXingRui
15  * @Date:2019/1/24
16  * @Description:
17  **/
18 public class TestMybatisDemo {
19     private static Logger logger = LogManager.getLogger(TestMybatisDemo.class);
20 
21     // 直接执行SQL语句
22     @Test
23     public void testMybatisSelectOne() {
24         String sql = "select user_name from t_admin_user where id = 2";
25         ISqlMapper sqlMapper = MybatisUtils.getMapper(ISqlMapper.class);
26         String name = sqlMapper.selectOne(sql);
27         logger.info(name);
28     }
29 
30     // 多个查询
31     @Test
32     public void testMybatisSelectList() {
33         String sql = "select user_name from t_admin_user";
34         ISqlMapper sqlMapper = MybatisUtils.getMapper(ISqlMapper.class);
35         List list = sqlMapper.selectList(sql);
36         logger.info(list);
37     }
38 
39     // 删除与插入
40     @Test
41     public void testMybatisDeleteInsert() {
42         ISqlMapper sqlMapper = MybatisUtils.getMapper(ISqlMapper.class);
43 
44         String deleteSql = "delete from t_admin_user  WHERE user_name = ‘testuser‘;";
45         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‘);";
46         int n = sqlMapper.delete(deleteSql);
47         logger.info("删除数据：" + n);
48         n = sqlMapper.insert(insertSql);
49         logger.info("插入数据：" + n);
50 //        MybatisUtils.getSession().commit();
51     }
52 
53 }

 

自己封装的Mybatis工具类（MybatisUtils.class）

 1 package testTraffic.utils;
 2 
 3 import org.apache.ibatis.io.Resources;
 4 import org.apache.ibatis.session.SqlSession;
 5 import org.apache.ibatis.session.SqlSessionFactory;
 6 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 7 
 8 import java.io.IOException;
 9 import java.io.InputStream;
10 
11 /**
12  * @Description: 生成mybatis的session对象
13  **/
14 public class MybatisUtils {
15     private static String resource = "config/mybatis-config-dao.xml";
16     private static SqlSessionFactory sqlSessionFactory = null;
17     private static SqlSession session = null;
18 
19 
20     private static void init() {
21         try {
22             InputStream inputStream = Resources.getResourceAsStream(resource);
23 //            创建工厂
24             sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
25 //            创建session对象
26             session = sqlSessionFactory.openSession(true);
27         } catch (IOException e) {
28             e.printStackTrace();
29         }
30     }
31 
32     public static SqlSession getSession() {
33         if (session == null) {
34             init();
35         }
36         return session;
37     }
38 
39     public static void close() {
40         if (session != null) {
41             session.close();
42             session = null;
43         }
44     }
45 
46     public static <T> T getMapper(Class<T> tClass) {
47         if (session == null) {
48             init();
49         }
50         return session.getMapper(tClass);
51     }
52 
53     public static void commit() {
54         if (session != null) {
55             session.commit();
56         }
57     }
58 
59 
60 }