這是語(yǔ)句！

    select c2.id as first_id,
    c2.name as first_name,
    c2.create_time as first_create_time,
    c1.id as second_id,
    c1.name as second_name,
    c1.create_time as second_create_time
    from category c1 right join category c2 on c1.parent_id=c2.id where
    c2.parent_id is null;

這個(gè)是我自己寫(xiě)的映射文件！

    <resultMap type="Category" id="p1">
    <id property="id" column="first_id" />
    <result property="name" column="second_name"></result>
    <result property="createTime" column="first_create_time" />
    <collection property="category" javaType="java.util.List"
        ofType="Category">
        <id property="id" column="second_id" />
        <result property="name" column="second_name" />
        <result property="createTime" column="second_create_time" />
    </collection>
</resultMap>

這個(gè)是實(shí)體類(lèi)類(lèi)名就叫Category

private Integer id;
private String name;
private Date createTime;
private List<Category> category;