1. 逆向工程
正向工程:先创建Java实体类,由框架负责根据实体类生成数据库表。 Hibernate是支持正向工程的。
逆向工程:先创建数据库表,由框架负责根据数据库表,反向生成如下资源:
- Java实体类
- Mapper接口
- Mapper映射文件
2. 创建逆向工程的步骤
1)添加依赖和插件
<!-- 依赖MyBatis核心包 -->
<dependencies>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.7</version>
</dependency>
<!-- junit测试 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!-- log4j日志 -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.16</version>
</dependency>
</dependencies>
<!-- 控制Maven在构建过程中相关配置 -->
<build>
<!-- 构建过程中用到的插件 -->
<plugins>
<!-- 具体插件,逆向工程的操作是以构建过程中插件形式出现的 -->
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.0</version>
<!-- 插件的依赖 -->
<dependencies>
<!-- 逆向工程的核心依赖 -->
<dependency>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-core</artifactId>
<version>1.3.2</version>
</dependency>
<!-- MySQL驱动 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.16</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
2)创建MyBatis的核心配置文件 mybatis-config.xml
3)创建逆向工程的配置文件 generatorConfig.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
<!--
targetRuntime: 执行生成的逆向工程的版本
MyBatis3Simple: 生成基本的CRUD(清新简洁版)
MyBatis3: 生成带条件的CRUD(奢华尊享版)
-->
<context id="DB2Tables" targetRuntime="MyBatis3">
<!-- 数据库的连接信息 -->
<jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
connectionURL="jdbc:mysql://localhost:3306/ssm?serverTimezone=UTC"
userId="root"
password="123456">
</jdbcConnection>
<!-- javaBean的生成策略-->
<javaModelGenerator targetPackage="com.mybatis.pojo"
targetProject=".\src\main\java">
<property name="enableSubPackages" value="true" />
<property name="trimStrings" value="true" />
</javaModelGenerator>
<!-- SQL映射文件的生成策略 -->
<sqlMapGenerator targetPackage="com.mybatis.mapper"
targetProject=".\src\main\resources">
<property name="enableSubPackages" value="true" />
</sqlMapGenerator>
<!-- Mapper接口的生成策略 -->
<javaClientGenerator type="XMLMAPPER"
targetPackage="com.mybatis.mapper" targetProject=".\src\main\java">
<property name="enableSubPackages" value="true" />
</javaClientGenerator>
<!-- 逆向分析的表 -->
<!-- tableName设置为*号,可以对应所有表,此时不写domainObjectName -->
<!-- domainObjectName属性指定生成出来的实体类的类名 -->
<table tableName="t_emp" domainObjectName="Emp"/>
<table tableName="t_dept" domainObjectName="Dept"/>
</context>
</generatorConfiguration>
4)执行MBG插件的generate目标(双击)
5)测试
public class MBGTest {
@Test
public void testMBG(){
SqlSession sqlSession = SqlSessionUtil.getSqlSession();
EmpMapper mapper = sqlSession.getMapper(EmpMapper.class);
//根据id查询数据
/*Emp emp = mapper.selectByPrimaryKey(1);
System.out.println(emp);*/
//查询所有数据
/*List<Emp> list = mapper.selectByExample(null);
list.forEach(System.out::println);*/
//根据条件查询数据
/*EmpExample example = new EmpExample();
example.createCriteria().andEmpNameEqualTo("张三").andAgeGreaterThanOrEqualTo(20);
example.or().andGenderEqualTo("男");
List<Emp> list = mapper.selectByExample(example);
list.forEach(System.out::println);*/
Emp emp = new Emp(1, "小黑", null, "女");
//测试普通修改功能
//mapper.updateByPrimaryKey(emp);
//测试选择性修改
mapper.updateByPrimaryKeySelective(emp);
}
}
标签:逆向,generator,工程,mapper,list,mybatis,emp,MyBatis From: https://www.cnblogs.com/Joyce-mi7/p/16649879.html