千锋JAVA教程系列:Mybatis-plus 千锋教育java教材

<dependency>

<groupId>com.baomidou</groupId>

<artifactId>mybatis-plus-boot-starter</artifactId>

<version>3.4.0</version>

</dependency>

<dependency>

<groupId>com.baomidou</groupId>

<artifactId>mybatis-plus</artifactId>

<version>3.4.0</version>

</dependency>

-- 创建测试表

DROP TABLE IF EXISTS tb_user;

CREATE TABLE user

(

id BIGINT(20) NOT NULL COMMENT '主键ID',

name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',

age INT(11) NULL DEFAULT NULL COMMENT '年龄',

email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',

PRIMARY KEY (id)

);

-- 插?测试数据

INSERT INTO user (id, name, age, email) VALUES

(1, 'Jone', 18, 'test1@baomidou.com'),

(2, 'Jack', 20, 'test2@baomidou.com'),

(3, 'Tom', 28, 'test3@baomidou.com'),

(4, 'Sandy', 21, 'test4@baomidou.com'),

(5, 'Billie', 24, 'test5@baomidou.com');

<dependencies>

<!-- mybatis-plus插件依赖 -->

<dependency>

<groupId>com.baomidou</groupId>

<artifactId>mybatis-plus</artifactId>

<version>3.1.1</version>

</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?具包-->

<dependency>

<groupId>org.projectlombok</groupId>

<artifactId>lombok</artifactId>

<version>1.18.4</version>

2.4 Mybatis + MP

下?演示，通过纯Mybatis与Mybatis-Plus整合。

创建?Module

</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>

</dependencies>

<build>

<plugins>

<plugin>

<groupId>org.apache.maven.plugins</groupId>

<artifactId>maven-compiler-plugin</artifactId>

<configuration>

<source>1.8</source>

<target>1.8</target>

</configuration>

</plugin>

</plugins>

</build>

<?xml version="1.0" encoding="UTF-8" ?>

<project xmlns="http://maven.apache.org/POM/4.0.0"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://maven.apache.org/POM/4.0.0

http://maven.apache.org/xsd/maven-4.0.0.xsd">

<parent>

<artifactId>lagou-mybatis-plus</artifactId>

<groupId>com.lagou.mp</groupId>

<version>1.0-SNAPSHOT</version>

</parent>

<modelVersion>4.0.0</modelVersion>

Mybatis实现查询User

第?步，编写mybatis-config.xml?件：

<artifactId>lagou-mybatis-plus-simple</artifactId>

</project>

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

<?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>

<properties resource="jdbc.properties"></properties>

<!--environments: 运?环境-->

<environments default="development">

<environment id="development">

<!--当前的事务事务管理器是JDBC-->

<transactionManager type="JDBC"></transactionManager>

<!--数据源信息 POOLED：使?mybatis的连接池-->

<dataSource type="POOLED">

<property name="driver" value="${jdbc.driver}"/>

<property name="url" value="${jdbc.url}"/>

<property name="username" value="${jdbc.username}"/>

<property name="password" value="${jdbc.password}"/>

</dataSource>

</environment>

</environments>

<!--引?映射配置?件-->

<mappers>

<mapper resource="mapper/UserMapper.xml"></mapper>

</mappers>

</configuration>

@Data // getter setter @toString

@NoArgsConstructor

@AllArgsConstructor

public class User {

private Long id;

private String name;

private Integer age;

private String email; }

public interface UserMapper {

List<User> findAll();

}

<?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="com.zy.mapper.UserMapper">

<!-- 查询所有 -->

<select id="findAll" resultType="com.zy.pojo.User">

select * from user

</select>

</mapper>

public class MPTest {

@Test

public void test1() throws IOException {

InputStream resourceAsStream =

Resources.getResourceAsStream("sqlMapConfig.xml");测试结果：

注：如果实体类名称和表名称不?致，可以在实体类上添加注解@TableName("指定数据库表名")

SqlSessionFactory sqlSessionFactory = new

SqlSessionFactoryBuilder().build(resourceAsStream);

SqlSession sqlSession = sqlSessionFactory.openSession();

UserMapper mapper = sqlSession.getMapper(UserMapper.class);

List<User> all = mapper.findAll();

for (User user : all) {

System.out.println(user);

}

}

}

import com.baomidou.mybatisplus.core.mapper.BaseMapper;

import com.zy.pojo.User;

public interface UserMapper extends BaseMapper<User> {

}

@Test

public void test2() throws IOException {

InputStream resourceAsStream =

Resources.getResourceAsStream("sqlMapConfig.xml");

//这?使?的是MP中的MybatisSqlSessionFactoryBuilder

SqlSessionFactory sqlSessionFactory = new

MybatisSqlSessionFactoryBuilder().build(resourceAsStream);

SqlSession sqlSession = sqlSessionFactory.openSession();

UserMapper mapper = sqlSession.getMapper(UserMapper.class);

// 可以调?BaseMapper中定义的?法

List<User> all = mapper.selectList(null);

for (User user : all) {

System.out.println(user);

}

}