假如要使用updateByPrimaryKeySelective方法（根據ID更新表）

xml檔案如下：

 <update id="updateByPrimaryKeySelective" parameterType="schooloa.bean.TrainingProgram">
    update trainingprogram
    <set>
      <if test="professional != null">
        professional = #{professional,jdbcType=VARCHAR},
      </if>
      <if test="grade != null">
        grade = #{grade,jdbcType=VARCHAR},
      </if>
      <if test="courseno != null">
        courseno = #{courseno,jdbcType=VARCHAR},
      </if>
      <if test="coursename != null">
        coursename = #{coursename,jdbcType=VARCHAR},
      </if>
      <if test="credit != null">
        credit = #{credit,jdbcType=DOUBLE},
      </if>
      <if test="totalhour != null">
        totalhour = #{totalhour,jdbcType=DOUBLE},
      </if>
      <if test="theoryhour != null">
        theoryhour = #{theoryhour,jdbcType=DOUBLE},
      </if>
      <if test="experimenthour != null">
        experimenthour = #{experimenthour,jdbcType=DOUBLE},
      </if>
      <if test="computerhour != null">
        computerhour = #{computerhour,jdbcType=DOUBLE},
      </if>
      <if test="testform != null">
        testform = #{testform,jdbcType=VARCHAR},
      </if>
      <if test="coursetype != null">
        coursetype = #{coursetype,jdbcType=VARCHAR},
      </if>
      <if test="beginsemester != null">
        beginsemester = #{beginsemester,jdbcType=VARCHAR},
      </if>
      <if test="syllabuspath != null">
        syllabuspath = #{syllabuspath,jdbcType=VARCHAR},
      </if>
      <if test="teachingplanpath != null">
        teachingplanpath = #{teachingplanpath,jdbcType=VARCHAR},
      </if>
      <if test="createtime != null">
        createtime = #{createtime,jdbcType=TIMESTAMP},
      </if>
    </set>
    where id = #{id,jdbcType=INTEGER}
  </update>
 

對應的Mapper裡面的方法為：

 int updateByExampleSelective(@Param("record") TrainingProgram record, @Param("example") TrainingProgramExample example);

Service

public int UpdateTrinPro(TrainingProgram trainingProgram,TrainingProgramExample trainingProgramExample)
	{
		Criteria s= trainingProgramExample.createCriteria();
		s.andIdEqualTo(trainingProgram.getId());//表示條件，id=trainingProgram.getId()
		return    trainingProgramMapper.updateByExampleSelective(trainingProgram,trainingProgramExample);
	}
 

Example使用：

TrainingProgramExample tpe=new TrainingProgramExample();

Criteria s= tpe.createCriteria();

s.andIdEqualTo(trainingProgram.getId());

trainingProgramMapper.updateByExampleSelective(trainingProgram,trainingProgramExample);

JunitTest

public void test1()
	{
		TrainingProgram trainingProgram=new TrainingProgram();
		trainingProgram.setId(40);
		trainingProgram.setProfessional("農學");
		TrainingProgramExample trainingProgramExample=new TrainingProgramExample();
		int count=trainingProgramService.UpdateTrinPro(trainingProgram, trainingProgramExample);
		if (count>0) {
			System.out.println("成功");
			
		}else
		{
			System.out.println("失敗");
		}
	}