MyBtis之关于#{}和${}，mybatis一对多

MyBtis之关于#{}和${}，mybatis一对多

1.${}的用法的mapper文件配置：

</select>
    <select id="selById2" resultType="com.susu.pojo.People" parameterType="com.susu.pojo.People">
  select * from people where id = ${id}
  </select>

测试的java代码：

People people = new People();
people.setId(1);
People one = session.selectOne("com.susu.mapper.PeopleMapper.selById2", people);
System.out.println(one);

运行效果：

可以看到，合成的sql是: select * form people where id = 1

2.#{}用法的mapper文件配置：

</select>
    <select id="selById2" resultType="com.susu.pojo.People" parameterType="com.susu.pojo.People">
  select * from people where id = #{id}
  </select>

运行效果：

总结#{}和${}的区别

注： ${}很少用，几乎不用！