mysql+mybatis 集合查询配置

mybatis映射配置文件：

主要：

<collection property="subCategories" column="category_id" ofType="com.school.domain.Category" resultMap="subCategories" />

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.school.dao.CategoryBeanMapper" >
  <resultMap id="BaseResultMap" type="com.school.domain.CategoryBean" >
    <id column="category_id" property="categoryId" jdbcType="VARCHAR" />
    <result column="parent_id" property="parentId" jdbcType="VARCHAR" />
    <result column="grade_id" property="gradeId" jdbcType="VARCHAR" />
    <result column="school_id" property="schoolId" jdbcType="VARCHAR" />
    <result column="name" property="name" jdbcType="VARCHAR" />
    <result column="description" property="description" jdbcType="VARCHAR" />
    <result column="link" property="link" jdbcType="VARCHAR" />
    <result column="icon" property="icon" jdbcType="VARCHAR" />
    <result column="ordered" property="ordered" jdbcType="INTEGER" />
    <result column="date_added" property="dateAdded" jdbcType="TIMESTAMP" />
    <result column="last_modified" property="lastModified" jdbcType="TIMESTAMP" />
    <result column="last_user_id" property="lastUserId" jdbcType="VARCHAR" />
    <result column="is_open" property="isOpen" jdbcType="VARCHAR" />
    <result column="status" property="status" jdbcType="VARCHAR" />
    <result column="category_type" property="categoryType" jdbcType="VARCHAR" />
    <collection property="subCategories" column="category_id" ofType="com.school.domain.Category" resultMap="subCategories" />
  </resultMap>
  
  <resultMap id="subCategories" type="com.school.domain.Category" >
    <id column="category_categoryId" property="categoryId" jdbcType="VARCHAR" />
    <result column="category_parentId" property="parentId" jdbcType="VARCHAR" />
    <result column="category_gradeId" property="gradeId" jdbcType="VARCHAR" />
    <result column="category_schoolId" property="schoolId" jdbcType="VARCHAR" />
    <result column="category_name" property="name" jdbcType="VARCHAR" />
    <result column="category_description" property="description" jdbcType="VARCHAR" />
    <result column="category_link" property="link" jdbcType="VARCHAR" />
    <result column="category_icon" property="icon" jdbcType="VARCHAR" />
    <result column="category_ordered" property="ordered" jdbcType="INTEGER" />
    <result column="category_date_added" property="dateAdded" jdbcType="TIMESTAMP" />
    <result column="category_last_modified" property="lastModified" jdbcType="TIMESTAMP" />
    <result column="category_last_user_id" property="lastUserId" jdbcType="VARCHAR" />
    <result column="category_is_open" property="isOpen" jdbcType="VARCHAR" />
    <result column="category_status" property="status" jdbcType="VARCHAR" />
    <result column="category_category_type" property="categoryType" jdbcType="VARCHAR" />
  </resultMap>
  
  <!-- 查询所用专题目录  -->
  <select id="selectByPrimaryKey" resultMap="BaseResultMap">
  	SELECT c.category_id, c.parent_id, c.grade_id, c.school_id, c.name, c.description, c.link, 
	  	c.icon, c.ordered, c.date_added, c.last_modified, c.last_user_id, c.category_type,
	    sub.category_id AS category_categoryId, sub.parent_id AS category_parentId, sub.grade_id AS category_gradeId, sub.school_id AS category_schoolId, 
	    sub.name AS category_name, sub.description AS category_description, sub.link AS category_link, sub.icon AS category_icon, sub.ordered AS category_ordered, 
	    sub.date_added AS category_dateAdded, sub.last_modified AS category_lastModified, sub.last_user_id AS category_lastUserId, sub.category_type AS category_category_type
    FROM category AS c
    LEFT JOIN category AS sub ON(c.category_id = sub.parent_id)
    WHERE c.grade_id = 1
    <if test="categoryId != null">
    	AND c.category_id=#{categoryId,jdbcType=VARCHAR}
    </if>
    <if test="schoolId != null">
    	AND c.school_id=#{schoolId,jdbcType=VARCHAR}
    </if>
  </select>
  
  <select id="selectByCategoryType" resultMap="BaseResultMap">
  	SELECT c.category_id, c.parent_id, c.grade_id, c.school_id, c.name, c.description, c.link, 
	  	c.icon, c.ordered, c.date_added, c.last_modified, c.last_user_id, c.category_type,
	    sub.category_id AS category_categoryId, sub.parent_id AS category_parentId, sub.grade_id AS category_gradeId, sub.school_id AS category_schoolId, 
	    sub.name AS category_name, sub.description AS category_description, sub.link AS category_link, sub.icon AS category_icon, sub.ordered AS category_ordered, 
	    sub.date_added AS category_dateAdded, sub.last_modified AS category_lastModified, sub.last_user_id AS category_lastUserId, sub.category_type AS category_category_type
    FROM category AS c
    LEFT JOIN category AS sub ON(c.category_id = sub.parent_id)
    WHERE c.grade_id = 1
    <if test="categoryType != null">
    	AND c.category_type=#{categoryType,jdbcType=VARCHAR}
    </if>
    <if test="schoolId != null">
    	AND c.school_id=#{schoolId,jdbcType=VARCHAR}
    </if>
  </select>

</mapper>

javabean:

package com.school.domain;

import java.util.List;

/**
 * 一级栏目及其二级栏目
 * @author FeiFan.Lin
 */
public class CategoryBean extends Category{

	private List<Category> subCategories;

	public List<Category> getSubCategories() {
		return subCategories;
	}

	public void setSubCategories(List<Category> subCategories) {
		this.subCategories = subCategories;
	}

}

Category:

package com.school.domain;

import java.util.Date;

public class Category {
    private String categoryId;

    private String parentId;

    private String gradeId;

    private String schoolId;

    private String name;

    private String description;

    private String link;

    private String icon;

    private Integer ordered;

    private Date dateAdded;

    private Date lastModified;

    private String lastUserId;

    private String isOpen;

    private String status;

    private String categoryType;

    public String getCategoryId() {
        return categoryId;
    }

    public void setCategoryId(String categoryId) {
        this.categoryId = categoryId == null ? null : categoryId.trim();
    }

    public String getParentId() {
        return parentId;
    }

    public void setParentId(String parentId) {
        this.parentId = parentId == null ? null : parentId.trim();
    }

    public String getGradeId() {
        return gradeId;
    }

    public void setGradeId(String gradeId) {
        this.gradeId = gradeId == null ? null : gradeId.trim();
    }

    public String getSchoolId() {
        return schoolId;
    }

    public void setSchoolId(String schoolId) {
        this.schoolId = schoolId == null ? null : schoolId.trim();
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description == null ? null : description.trim();
    }

    public String getLink() {
        return link;
    }

    public void setLink(String link) {
        this.link = link == null ? null : link.trim();
    }

    public String getIcon() {
        return icon;
    }

    public void setIcon(String icon) {
        this.icon = icon == null ? null : icon.trim();
    }

    public Integer getOrdered() {
        return ordered;
    }

    public void setOrdered(Integer ordered) {
        this.ordered = ordered;
    }

    public Date getDateAdded() {
        return dateAdded;
    }

    public void setDateAdded(Date dateAdded) {
        this.dateAdded = dateAdded;
    }

    public Date getLastModified() {
        return lastModified;
    }

    public void setLastModified(Date lastModified) {
        this.lastModified = lastModified;
    }

    public String getLastUserId() {
        return lastUserId;
    }

    public void setLastUserId(String lastUserId) {
        this.lastUserId = lastUserId == null ? null : lastUserId.trim();
    }

    public String getIsOpen() {
        return isOpen;
    }

    public void setIsOpen(String isOpen) {
        this.isOpen = isOpen == null ? null : isOpen.trim();
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status == null ? null : status.trim();
    }

    public String getCategoryType() {
        return categoryType;
    }

    public void setCategoryType(String categoryType) {
        this.categoryType = categoryType == null ? null : categoryType.trim();
    }
}