Mybatis 批量insert

<insert id="insert" parameterType="ArrayList">

insert into XXX(id,name,type)

<foreach collection="list" item="item" index="index" separator="union all">

select #{item.id,jdbcType=INTEGER},#{item.name,jdbcType=VARCHAR},#{item.type,jdbcType=INTEGER} from dual

</foreach>

</insert>

dao:

public Integer insert(List<User> list){

return sqlSession.insert("userMapper.insert",list);

}