2021-03-21

MyBatis-Plus创建

创建数据库

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

创建Maven工程
在这里插入图片描述
导入依赖

</dependency><!-- MySql --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.47</version></dependency><!-- 连接池 --><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.0.11</version></dependency><!--简化bean代码的工具包--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional><version>1.18.4</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-log4j12</artifactId><version>1.6.4</version></dependency>

创建子Module
在这里插入图片描述

准备日志文件log4j.properties
在这里插入图片描述

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

编写mybatis-confing.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration><environments default="development"><environment id="development"><transactionManager type="JDBC"/><dataSource type="POOLED"><property name="driver" value="com.mysql.jdbc.Driver"/><property name="url"value="jdbc:mysql://127.0.0.1:3306/db_user?useUnicode=true&amp;characterEncoding=utf8&amp;autoReconnect=true&amp;allowMultiQueries=true&amp;useSSL=false"/><property name="username" value="root"/><property name="password" value="x5"/></dataSource></environment></environments><mappers><mapper resource="UserMapper.xml"/></mappers>
</configuration>

编写User实体对象（在User对象中添加@TableName，指定数据库表名tb_user）

import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;@Data
@NoArgsConstructor
@AllArgsConstructor
@TableName("tb_user")
public class User {private Long id;private String userName;private String password;private String name;private Integer age;private String email;
}

编写UserMapper接口（将UserMapper继承BaseMapper）

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.r.mp.simple.pojo.User;import java.util.List;public interface UserMapper extends BaseMapper<User> {List<User> findAll();
}

编写UserMapper.xml

<mapper namespace="com.r.mp.simple.mapper.UserMapper"><select id="findAll" resultType="com.r.mp.simple.pojo.User">select * from tb_user</select>
</mapper>

编写测试用例TestMybatisPlus

import com.baomidou.mybatisplus.core.MybatisSqlSessionFactoryBuilder;
import com.r.mp.simple.mapper.UserMapper;
import com.r.mp.simple.pojo.User;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.junit.Test;import java.io.InputStream;
import java.util.List;public class TestMybatisPlus {@Testpublic void testUserList() throws Exception {String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = newMybatisSqlSessionFactoryBuilder().build(inputStream);SqlSession sqlSession = sqlSessionFactory.openSession();UserMapper userMapper = sqlSession.getMapper(UserMapper.class);List<User> list = userMapper.selectList(null);for (User user : list) {System.out.println(user);}}}