MyBatis Plus 入门使用详细教程

DROP TABLE IF EXISTS `tbl_employee`;
CREATE TABLE `tbl_employee` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `last_name` varchar(50) DEFAULT NULL,
 `email` varchar(50) DEFAULT NULL,
 `gender` char(1) DEFAULT NULL,
 `age` int(11) DEFAULT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8;

 <dependencies>
 <!-- MP -->
 <dependency>
  <groupId>com.baomidou</groupId>
  <artifactId>mybatis-plus</artifactId>
  <version>2.3</version>
 </dependency>
 <!-- 测试 -->
 <dependency>
  <groupId>junit</groupId>
  <artifactId>junit</artifactId>
  <version>4.12</version>
 </dependency>
 <!-- 数据源 -->
 <dependency>
  <groupId>com.alibaba</groupId>
  <artifactId>druid</artifactId>
  <version>1.1.10</version>
 </dependency>
 <!-- 数据库驱动 -->
 <dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>5.1.39</version>
 </dependency>
 <!-- Spring 相关 -->
 <dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context</artifactId>
  <version>4.3.9.RELEASE</version>
 </dependency>
 <dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-orm</artifactId>
  <version>4.3.9.RELEASE</version>
 </dependency>
 </dependencies>

<?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">
<!-- 不作任何配置 -->
<configuration />

jdbc.url=jdbc:mysql://localhost:3306/mp
jdbc.username=root
jdbc.password=1234

<!-- 数据源 -->
 <context:property-placeholder location="classpath:db.properties"/>
 <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
 <property name="url" value="${jdbc.url}"></property>
 <property name="username" value="${jdbc.username}"></property>
 <property name="password" value="${jdbc.password}"></property>
 </bean>

 <!-- MP 提供的 MybatisSqlSessionFactoryBean -->
 <bean id="sqlSessionFactoryBean" 
  class="com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean">
 <!-- 数据源 -->
 <property name="dataSource" ref="dataSource"></property>
 <!-- mybatis 全局配置文件 -->
 <property name="configLocation" value="classpath:mybatis-config.xml"></property>
 <!-- 别名处理 -->
 <property name="typeAliasesPackage" value="com.jas.bean"></property>
 <!-- 注入全局MP策略配置 -->
 <property name="globalConfig" ref="globalConfiguration"></property>
 <!-- 插件注册 -->
 <property name="plugins">
  <list>
  <!-- 注册分页插件 -->
  <bean class="com.baomidou.mybatisplus.plugins.PaginationInterceptor" />
  <!-- 注入 SQL 性能分析插件，建议在开发环境中使用，可以在控制台查看 SQL 执行日志 -->
  <bean class="com.baomidou.mybatisplus.plugins.PerformanceInterceptor">
   <property name="maxTime" value="1000" />
   <!--SQL 是否格式化 默认false-->
   <property name="format" value="true" />
  </bean>
  </list>
 </property>
 </bean>

 <!-- 定义 MybatisPlus 的全局策略配置-->
 <bean id ="globalConfiguration" class="com.baomidou.mybatisplus.entity.GlobalConfiguration">
 <!-- 在 2.3 版本以后，dbColumnUnderline 默认值是 true -->
 <property name="dbColumnUnderline" value="true"></property>
 <!-- 全局的主键策略 -->
 <property name="idType" value="0"></property>
 <!-- 全局的表前缀策略配置 -->
 <property name="tablePrefix" value="tbl_"></property>
 </bean>
 
 <!-- 配置mybatis 扫描mapper接口的路径 -->
 <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
 <property name="basePackage" value="com.jas.mapper"></property>
 </bean>

@TableName(value = "tbl_employee")
public class Employee {
 @TableId(value = "id", type = IdType.AUTO)
 private Integer id;
 @TableField(value = "last_name")
 private String lastName;
 private String email;
 private Integer gender;
 private Integer age;

 public Employee() {
 super();
 }
 
 public Employee(Integer id, String lastName, String email, Integer gender, Integer age) {
 this.id = id;
 this.lastName = lastName;
 this.email = email;
 this.gender = gender;
 this.age = age;
 }
 // 省略 set、get 与 toString() 方法

/**
* 不定义任何接口方法
*/
public interface EmployeeMapper extends BaseMapper<Employee> {}

private ApplicationContext context = 
  new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
  
 private EmployeeMapper employeeMapper = 
  context.getBean("employeeMapper", EmployeeMapper.class);

 @Test
 public void getEmpByIdTest() {
 Employee employee = employeeMapper.selectById(1);
 
 System.out.println(employee);
 }

 @Test
 public void getEmpByPage() {
 Page<?> page = new Page<>(1, 5);
 List<Employee> list = employeeMapper.selectPage(page, null);
 
 System.out.println("总记录数：" + page.getTotal());
 System.out.println("总页数" + page.getPages());
 System.out.println(list);
 }

@Test
 public void getEmpByName() {
 EntityWrapper<Employee> wrapper = new EntityWrapper<>();
 
 // 'last_name' 与 'age' 对应数据库中的字段 
 wrapper.like("last_name", "张");
 wrapper.eq("age", 20);
 
 List<Employee> list = employeeMapper.selectList(wrapper);
 System.out.println(list);
 }