java脚本注释格式（java的三种注释类型）
Mybatis动态SQL
Mybatis，在带注解的映射器接口类中使用动态SQL，可使用script元素，即：&<script&>&</script&>。
案例代码
Model
package com.what21.mybatis.model;import lombok.Data;@Datapublic class Employee { // ID private Integer id; // 名称 private String name; // 邮箱 private String email; // 性别 private String gender; // 年龄 private Integer age;}Mapper&<映射器接口&>
package com.what21.mybatis.demo03.mapper;import com.what21.mybatis.model.Employee;import org.apache.ibatis.annotations.*;import java.util.List;public interface EmployeeMapper { @Select(value = "select * from `employee` where id = #{id}") @ResultType(Employee.class) public Employee findEmployeeById(Integer id); @Update(value = "&<script&>" + "update `employee` " + " &<set&>" + " &<if test='name != null'&>" + " `name`=#{name}," + " &</if&>" + " &<if test='email != null'&>" + " `email`=#{email}," + " &</if&>" + " &<if test='gender != null'&>" + " `gender`=#{gender}," + " &</if&>" + " &<if test='age != null'&>" + " `age`=#{age} " + " &</if&>" + " &</set&>" + "where id = #{id}" + "&</script&>") public int updateEmployee(Employee employee); @Delete(value = "&<script&>" + " delete from `employee` where id in" + " &<foreach collection='idList' item='id' open='(' separator=',' close=')'&>" + " #{id}" + " &</foreach&>" + "&</script&>") public int deleteEmployeeByIds(@Param("idList") List&<Integer&> idList);}配置文件：
&<?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&> &<settings&> &<!--建议显示的指定需要配置的值，防止版本更新带来的问题--&> &<!--开启驼峰命名规则--&> &<setting name="mapUnderscoreToCamelCase" value="true"/&> &</settings&> &<typeAliases&> &<typeAlias type="com.what21.mybatis.model.Employee" alias="employee"/&> &</typeAliases&> &<plugins&> &<plugin interceptor="com.github.pagehelper.PageInterceptor"&> &<!--默认值为 false，当该参数设置为 true 时，如果 pageSize=0 或者 RowBounds.limit = 0 就会查询出全部的结果--&> &<!--如果某些查询数据量非常大，不应该允许查出所有数据--&> &<property name="pageSizeZero" value="true"/&> &</plugin&> &</plugins&> &<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://localhost:3306/demo?characterEncoding=UTF8&&useSSL=false&&serverTimezone=UTC&&rewriteBatchedStatements=true"/&> &<property name="username" value="root"/&> &<property name="password" value="root"/&> &</dataSource&> &</environment&> &</environments&> &<mappers&> &<mapper class="com.what21.mybatis.demo03.mapper.EmployeeMapper" /&> &</mappers&>&</configuration&>测试类&<main方法测试&>：
package com.what21.mybatis.demo03;import com.what21.mybatis.demo03.mapper.EmployeeMapper;import com.what21.mybatis.model.Employee;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import java.io.IOException;import java.io.Reader;import java.util.Arrays;import java.util.List;public class MybatisDemoMain { /** * 创建sessionFactory * * @param mybatisConfig * @return */ private static SqlSessionFactory getSessionFactory(String mybatisConfig) { SqlSessionFactory sessionFactory = null; try { Reader reader = Resources.getResourceAsReader(mybatisConfig); sessionFactory = new SqlSessionFactoryBuilder().build(reader); } catch (IOException e) { e.printStackTrace(); } return sessionFactory; } public static void main(String&[] args) { String resource = "com/what21/mybatis/demo03/mybatisConfig.xml"; // 从SessionFactory中获取SqlSession SqlSession sqlSession = getSessionFactory(resource).openSession(); // Mapper EmployeeMapper employeeMapper = sqlSession.getMapper(EmployeeMapper.class); // select操作 Employee findEmployee = employeeMapper.findEmployeeById(2); System.out.println(findEmployee); findEmployee.setName("学习测试demo"); findEmployee.setEmail("leran@demo.com"); findEmployee.setAge(34); findEmployee.setGender("1"); int updateOperate = employeeMapper.updateEmployee(findEmployee); System.out.println("update操作结果：" + updateOperate); List&<Integer&> idsList = Arrays.asList(findEmployee.getId()); // delete操作 int deleteOperate = employeeMapper.deleteEmployeeByIds(idsList); // SQL正确，没有删除任何一条数据，返回结果为：0 System.out.println("delete操作结果：" + deleteOperate); // 提交 //sqlSession.commit(); }}