SSM-Mybatis的SQL（增删改查）语句

id="xxx"对应为Dao层方法。须保证名字一致

一、增

传入对象，使用#{对象的属性}

useGeneratedKeysID是否自增

<insert id="registerUser" keyProperty="id" useGeneratedKeys="true">
insert into user values(default,#{username},#{password},#{sex},#{regtime},#{type})
</insert>

二、删

如果就一个参数，推荐使用#{0}的传参方式

<delete id="deleteMsg">
        delete from msg where id = #{0}
    </delete>

三、改

set后跟修改的数据。

<update id="updateReadMsg">
    update msg set isread = 1 where isread = 0 and uid = #{0};
   </update>

<updateid="updateReadMsg">
    update msg set isread = #{0} where isread = 0 and uid = #{1};
   </update>

四、查

如果实体对象的属性与数据库表的字段名一致，就不在需建立映射了

<resultMap type="com.***.mysmm.entity.Msg" id="msgMap">
</resultMap>

//order by 排序   查询出的list的排序

<select id="queryMsgbyUid" resultMap="msgMap">
select * from msg where uid = #{0} order by isread
</select>