示例代码:
接口定义: package com.mybatis.dao; import com.mybatis.bean.Employee; public interface EmployeeMapper { public void updateEmp(Employee employee); public void updateEmployee(Employee employee); } mapper定义: <?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.mybatis.dao.EmployeeMapper"> <update id="updateEmp"> update tbl_employee <set> <if test="lastName!=null"> last_name=#{lastName}, </if> <if test="email!=null"> email=#{email}, </if> <if test="gender!=null"> gender=#{gender} </if> </set> where id=#{id} </update> <update id="updateEmployee"> update tbl_employee <trim prefix="set" suffixOverrides=","> <if test="lastName!=null"> last_name=#{lastName}, </if> <if test="email!=null"> email=#{email}, </if> <if test="gender!=null"> gender=#{gender} </if> </trim> where id=#{id} </update> </mapper> 测试代码: package com.mybatis.demo; import com.mybatis.bean.Employee; import com.mybatis.dao.EmployeeMapper; 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 org.junit.Test; import java.io.IOException; import java.io.InputStream; import java.util.List; public class MyTest { public SqlSessionFactory getSqlSessionFactory() throws IOException { String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); return new SqlSessionFactoryBuilder().build(inputStream); } @Test public void test() throws IOException { SqlSessionFactory sqlSessionFactory = getSqlSessionFactory(); SqlSession openSession = sqlSessionFactory.openSession(true); try { EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class); mapper.updateEmp(new Employee(1, "good", null, null)); mapper.updateEmployee(new Employee(5, "test", null, null)); } finally { openSession.close(); } } }