Mybatis-Plus快速入门

ゝ一世哀愁。 2024-03-24 21:57 7阅读 0赞

#

目录

一、基础工程

1、创建一个数据库：mp

2、添加数据

3、创建初始工程

4、添加依赖

二、Mybatis + Mybatis-Plus

1、创建子工程：mybatis-plus-simple

2、在子工程下添加配置

2.1Mybatis实现查询User

2.1.1、编写User实体对象

2.1.2、编写UserMapper接口

2.1.3、编写UserMapper.xml文件

2.1.4、编写TestMybatis测试

2.2Mybatis+MP实现查询User

2.2.1、将UserMapper继承BaseMapper，将拥有了BaseMapper中的所有方法

2.2.2、使用MP中的MybatisSqlSessionFactoryBuilder进程构建

三、Spring + Mybatis + Mybatis-Plus

1、创建子Module

2、添加pom文件

3、编写jdbc.properties

4、编写applicationContext.xml

5、编写User对象以及UserMapper接口

6、编写测试类

四、SpringBoot + Mybatis + Mybatis-Plus

1、创建一个工springboot程

2、添加依赖

3、添加日志文件及配置

4、编写pojo

5、编写mapper

6、编写测试类

一、基础工程

1、创建一个数据库：mp

  1. create database if not exists mp;

2、添加数据

  1. -- 创建测试表
  2. CREATE TABLE `tb_user` (
  3. `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  4. `user_name` varchar(20) NOT NULL COMMENT '用户名',
  5. `password` varchar(20) NOT NULL COMMENT '密码',
  6. `name` varchar(30) DEFAULT NULL COMMENT '姓名',
  7. `age` int(11) DEFAULT NULL COMMENT '年龄',
  8. `email` varchar(50) DEFAULT NULL COMMENT '邮箱',
  9. PRIMARY KEY (`id`)
  10. ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
  11. -- 插入测试数据
  12. INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES
  13. ('1', 'zhangsan', '123456', '张三', '18', 'test1@itcast.cn');
  14. INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES
  15. ('2', 'lisi', '123456', '李四', '20', 'test2@itcast.cn');
  16. INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES
  17. ('3', 'wangwu', '123456', '王五', '28', 'test3@itcast.cn');
  18. INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES
  19. ('4', 'zhaoliu', '123456', '赵六', '21', 'test4@itcast.cn');
  20. INSERT INTO `tb_user` (`id`, `user_name`, `password`, `name`, `age`, `email`) VALUES
  21. ('5', 'sunqi', '123456', '孙七', '24', 'test5@itcast.cn');

3、创建初始工程

f755439555164d1d93f23f47ea9caa65.png

4、添加依赖

  1. <dependencies>
  2.         <!-- mybatis-plus插件依赖 -->
  3.         <dependency>
  4.             <groupId>com.baomidou</groupId>
  5.             <artifactId>mybatis-plus</artifactId>
  6.             <version>3.1.1</version>
  7.         </dependency>
  8.         <!-- MySql -->
  9.         <dependency>
  10.             <groupId>mysql</groupId>
  11.             <artifactId>mysql-connector-java</artifactId>
  12.             <version>5.1.47</version>
  13.         </dependency>
  14.         <!-- 连接池 -->
  15.         <dependency>
  16.             <groupId>com.alibaba</groupId>
  17.             <artifactId>druid</artifactId>
  18.             <version>1.0.11</version>
  19.         </dependency>
  20.         <!--简化bean代码的工具包-->
  21.         <dependency>
  22.             <groupId>org.projectlombok</groupId>
  23.             <artifactId>lombok</artifactId>
  24.             <optional>true</optional>
  25.             <version>1.18.4</version>
  26.         </dependency>
  27.         <dependency>
  28.             <groupId>junit</groupId>
  29.             <artifactId>junit</artifactId>
  30.             <version>4.12</version>
  31.         </dependency>
  32.         <dependency>
  33.             <groupId>org.slf4j</groupId>
  34.             <artifactId>slf4j-log4j12</artifactId>
  35.             <version>1.6.4</version>
  36.         </dependency>
  37.     </dependencies>
  38.     <build>
  39.         <plugins>
  40.             <plugin>
  41.                 <groupId>org.apache.maven.plugins</groupId>
  42.                 <artifactId>maven-compiler-plugin</artifactId>
  43.                 <configuration>
  44.                     <source>1.8</source>
  45.                     <target>1.8</target>
  46.                 </configuration>
  47.             </plugin>
  48.         </plugins>
  49.     </build>

二、Mybatis + Mybatis-Plus

1、创建子工程：mybatis-plus-simple

2、在子工程下添加配置

2.1Mybatis实现查询User

日之文件：log4j.properties

  1. log4j.rootLogger=DEBUG,A1
  2. log4j.appender.A1=org.apache.log4j.ConsoleAppender
  3. log4j.appender.A1.layout=org.apache.log4j.PatternLayout
  4. log4j.appender.A1.layout.ConversionPattern=[%t] [%c]-[%p] %m%n

mybatis-config.xml文件：

  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.     <environments default="development">
  7.         <environment id="development">
  8.             <transactionManager type="JDBC"/>
  9.             <dataSource type="POOLED">
  10.                 <property name="driver" value="com.mysql.jdbc.Driver"/>
  11.                 <property name="url" value="jdbc:mysql://127.0.0.1:3306/mp?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false"/>
  12.                 <property name="username" value="root"/>
  13.                 <property name="password" value="root"/>
  14.             </dataSource>
  15.         </environment>
  16.     </environments>
  17.     <mappers>
  18.         <mapper resource="UserMapper.xml"/>
  19.     </mappers>
  20. </configuration>
2.1.1、编写User实体对象
  1. package com.mp.pojo;
  3. import lombok.AllArgsConstructor;
  4. import lombok.Data;
  5. import lombok.NoArgsConstructor;
  7. @Data
  8. @NoArgsConstructor
  9. @AllArgsConstructor
  10. public class User {
  11.     private Long id;
  12.     private String userName;
  13.     private String password;
  14.     private String name;
  15.     private Integer age;
  16.     private String email;
  17. }
2.1.2、编写UserMapper接口
  1. public interface UserMapper {
  3.     List<User> findAll();
  4. }
2.1.3、编写UserMapper.xml文件
  1. <?xml version="1.0" encoding="UTF-8" ?>
  2. <!DOCTYPE mapper
  3.         PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  4.         "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
  5. <mapper namespace="com.mp.mapper.UserMapper">
  7.     <resultMap id="MappingName" type="com.mp.pojo.User">
  8.         <id property="id" column="id"/>
  9.         <result property="userName" column="user_name"/>
  10.         <result property="password" column="password"/>
  11.         <result property="name" column="name"/>
  12.         <result property="age" column="age"/>
  13.         <result property="email" column="email"/>
  14.     </resultMap>
  15.     <select id="findAll" resultMap="MappingName">
  16.         select * from tb_user
  17.     </select>
  18. </mapper>
2.1.4、编写TestMybatis测试
  1. public class TestMybatis {
  2.     @Test
  3.     public void testUserList() throws Exception{
  4.         //读取配置文件
  5.         String resource = "mybatis-config.xml";
  6.         //加载资源文件。
  7.         InputStream inputStream = Resources.getResourceAsStream(resource);
  8.         //创建 sqlSessionFactory 工厂
  9.         SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
  10.         //创建 SqlSession 对象
  11.         SqlSession sqlSession = sqlSessionFactory.openSession();
  12.         //获取一个 UserMapper 的实例
  13.         UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
  14.         //调用方法
  15.         List<User> list = userMapper.findAll();
  16.         for (User user : list) {
  17.             System.out.println(user);
  18.         }
  19.     }
  20. }
2.2Mybatis+MP实现查询User
2.2.1、将UserMapper继承BaseMapper，将拥有了BaseMapper中的所有方法
  1. public interface UserMapper extends BaseMapper<User> {
  3.     List<User> findAll();
  4. }
2.2.2、使用MP中的MybatisSqlSessionFactoryBuilder进程构建
  1. public class TestMybatisPlus {
  3.     @Test
  4.     public void testUserList() throws Exception{
  5.         //读取配置文件
  6.         String resource = "mybatis-config.xml";
  7.         //加载资源文件。
  8.         InputStream inputStream = Resources.getResourceAsStream(resource);
  9.         //这里使用的是mybatisplus中的MybatisSqlSessionFactoryBuilder
  10.         SqlSessionFactory sqlSessionFactory = new MybatisSqlSessionFactoryBuilder().build(inputStream);
  11.         //创建 SqlSession 对象
  12.         SqlSession sqlSession = sqlSessionFactory.openSession();
  13.         //获取一个 UserMapper 的实例
  14.         UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
  15.         // 可以调用BaseMapper中定义的方法
  16.         List<User> list = userMapper.selectList(null);
  17.         for (User user : list) {
  18.             System.out.println(user);
  19.         }
  20.     }
  22. }

三、Spring + Mybatis + Mybatis-Plus

1、创建子Module

696d1208e82b44d7b462de1cd0689409.png

2、添加pom文件

  1. <properties>
  2.         <maven.compiler.source>8</maven.compiler.source>
  3.         <maven.compiler.target>8</maven.compiler.target>
  4.         <spring.version>5.1.6.RELEASE</spring.version>
  5.     </properties>
  6.     <dependencies>
  7.         <dependency>
  8.             <groupId>org.springframework</groupId>
  9.             <artifactId>spring-webmvc</artifactId>
  10.             <version>${spring.version}</version>
  11.         </dependency>
  12.         <dependency>
  13.             <groupId>org.springframework</groupId>
  14.             <artifactId>spring-jdbc</artifactId>
  15.             <version>${spring.version}</version>
  16.         </dependency>
  17.         <dependency>
  18.             <groupId>org.springframework</groupId>
  19.             <artifactId>spring-test</artifactId>
  20.             <version>${spring.version}</version>
  21.         </dependency>
  22.     </dependencies>

3、编写jdbc.properties

  1. jdbc.driver=com.mysql.jdbc.Driver
  2. jdbc.url=jdbc:mysql://127.0.0.1:3306/mp?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false
  3. jdbc.username=root
  4. jdbc.password=root

4、编写applicationContext.xml

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <beans xmlns="http://www.springframework.org/schema/beans"
  3.        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  4.        xmlns:context="http://www.springframework.org/schema/context"
  5.        xsi:schemaLocation="http://www.springframework.org/schema/beans
  6.         http://www.springframework.org/schema/beans/spring-beans.xsd
  7.         http://www.springframework.org/schema/context
  8.         http://www.springframework.org/schema/context/spring-context.xsd">
  9.     <context:property-placeholder location="classpath:*.properties"/>
  10.     <!-- 定义数据源 -->
  11.     <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
  12.           destroy-method="close">
  13.         <property name="url" value="${jdbc.url}"/>
  14.         <property name="username" value="${jdbc.username}"/>
  15.         <property name="password" value="${jdbc.password}"/>
  16.         <property name="driverClassName" value="${jdbc.driver}"/>
  17.         <property name="maxActive" value="10"/>
  18.         <property name="minIdle" value="5"/>
  19.     </bean>
  20.     <!--这里使用MP提供的sqlSessionFactory，完成了Spring与MP的整合-->
  21.     <bean id="sqlSessionFactory"
  22.           class="com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean">
  23.         <property name="dataSource" ref="dataSource"/>
  24.     </bean>
  25.     <!--扫描mapper接口，使用的依然是Mybatis原生的扫描器-->
  26.     <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
  27.         <property name="basePackage" value="com.mybatisplus.mapper"/>
  28.     </bean>
  30. </beans>

5、编写User对象以及UserMapper接口

  1. @Data
  2. @NoArgsConstructor
  3. @AllArgsConstructor
  4. @TableName("tb_user")
  5. public class User {
  6.     private Long id;
  7.     private String userName;
  8.     private String password;
  9.     private String name;
  10.     private Integer age;
  11.     private String email;
  12. }
  14. public interface UserMapper extends BaseMapper<User> {
  15. }

6、编写测试类

  1. @RunWith(SpringJUnit4ClassRunner.class)
  2. @ContextConfiguration(locations = "classpath:applicationContext.xml")
  3. public class TestSpringMP {
  4.     @Autowired
  5.     private UserMapper userMapper;
  6.     @Test
  7.     public void testSelectList(){
  8.         List<User> users = this.userMapper.selectList(null);
  9.         for (User user : users) {
  10.             System.out.println(user);
  11.         }
  12.     }
  14. }

在teat下测试可能会读取不到 applicationContext.xml文件，复制一份放在teat目录下即可

52b924ab040740fb9a5b88d476423109.png

四、SpringBoot + Mybatis + Mybatis-Plus

1、创建一个工springboot程

7c2da97266a943acaa1aac101d98bc9c.png

2、添加依赖

  1. <dependencies>
  2.         <dependency>
  3.             <groupId>org.springframework.boot</groupId>
  4.             <artifactId>spring-boot-starter</artifactId>
  5.         </dependency>
  7.         <dependency>
  8.             <groupId>com.mysql</groupId>
  9.             <artifactId>mysql-connector-j</artifactId>
  10.             <scope>runtime</scope>
  11.         </dependency>
  12.         <dependency>
  13.             <groupId>org.projectlombok</groupId>
  14.             <artifactId>lombok</artifactId>
  15.             <optional>true</optional>
  16.         </dependency>
  17.         <dependency>
  18.             <groupId>org.springframework.boot</groupId>
  19.             <artifactId>spring-boot-starter-test</artifactId>
  20.             <scope>test</scope>
  21.         </dependency>
  22.         <!--mybatis-plus的springboot支持-->
  23.         <dependency>
  24.             <groupId>com.baomidou</groupId>
  25.             <artifactId>mybatis-plus-boot-starter</artifactId>
  26.             <version>3.1.1</version>
  27.         </dependency>
  28.         <dependency>
  29.             <groupId>org.slf4j</groupId>
  30.             <artifactId>slf4j-log4j12</artifactId>
  31.         </dependency>
  32.     </dependencies>

3、添加日志文件及配置

log4j.properties：

  1. log4j.rootLogger=DEBUG,A1
  2. log4j.appender.A1=org.apache.log4j.ConsoleAppender
  3. log4j.appender.A1.layout=org.apache.log4j.PatternLayout
  4. log4j.appender.A1.layout.ConversionPattern=[%t] [%c]-[%p] %m%n

编写application.properties文件：

  1. spring.application.name = itcast-mp-springboot
  2. spring.datasource.driver-class-name=com.mysql.jdbc.Driver
  3. spring.datasource.url=jdbc:mysql://127.0.0.1:3306/mp?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false
  4. spring.datasource.username=root
  5. spring.datasource.password=root

4、编写pojo

  1. @Data
  2. @NoArgsConstructor
  3. @AllArgsConstructor
  4. @TableName("tb_user")
  5. public class User {
  6.     private Long id;
  7.     private String userName;
  8.     private String password;
  9.     private String name;
  10.     private Integer age;
  11.     private String email;
  12. }

5、编写mapper

  1. public interface UserMapper extends BaseMapper<User> {
  2. }

6、编写测试类

  1. @Autowired
  2.     private UserMapper userMapper;
  3.     @Test
  4.     public void testSelect() {
  5.         List<User> userList = userMapper.selectList(null);
  6.         for (User user : userList) {
  7.             System.out.println(user);
  8.         }
  9.     }

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