mybatis递归 一对多的实现方法示例

CREATE TABLE `goods_category` ( `goodscateid` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) DEFAULT NULL, `parentid` int(11) DEFAULT NULL, `description` varchar(255) DEFAULT NULL, `displayorder` int(11) DEFAULT NULL, `commissionrate` double DEFAULT NULL, `enabled` int(11) DEFAULT NULL, PRIMARY KEY (`goodscateid`)) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8;/*Data for the table `goods_category` */insert into `goods_category`(`goodscateid`,`name`,`parentid`,`description`,`displayorder`,`commissionrate`,`enabled`) values (1,'java',0,'111',NULL,NULL,NULL),(2,'spring',1,'222',NULL,NULL,NULL),(3,'springmvc',1,'333',NULL,NULL,NULL),(4,'struts',1,'444',NULL,NULL,NULL),(5,'jdbc',0,'555',NULL,NULL,NULL),(6,'hibernate',5,'666',NULL,NULL,NULL),(7,'mybatis',5,'777',NULL,NULL,NULL),(8,'jdbctemplate',5,'888',NULL,NULL,NULL),(9,'beanfactory',3,'999',NULL,NULL,NULL),(10,'factorybean',3,'000',NULL,NULL,NULL);

@JsonIgnoreProperties({"displayorder","commissionrate","enabled"})public class GoodsCategoryVo { private Integer goodscateid; private String name; private Integer parentid; private String description; private Integer displayorder; private Double commissionrate; private Integer enabled; private List<GoodsCategoryVo> catelist;get 。。。 set。。。 tostring。。。

public interface GoodsMapper { List<GoodsCategoryVo> getCategory(Integer pid);}

<resultMap id="getSelf" type="com.bscc.beans.GoodsCategoryVo">  <id column="goodscateid" property="goodscateid"></id>  <result column="name" property="name"></result>  <collection property="catelist" select="getCategory"   column="goodscateid"></collection>  <!--查到的cid作为下次的pid --> </resultMap> <select id="getCategory" resultMap="getSelf">  select * from goods_category where parentid=#{pid}  ORDER BY displayorder,goodscateid </select>

@RequestMapping("/getGoodsList") @ResponseBody public List<GoodsCategoryVo> getGoodsList(){  // pid指定为0  List<GoodsCategoryVo> list = goodsMapper.getCategory(0);  return list; }

[ {  "goodscateid": 1,  "name": "java",  "parentid": 0,  "description": "111",  "catelist": [   {    "goodscateid": 2,    "name": "spring",    "parentid": 1,    "description": "222",    "catelist": []   },   {    "goodscateid": 3,    "name": "springmvc",    "parentid": 1,    "description": "333",    "catelist": [     {      "goodscateid": 9,      "name": "beanfactory",      "parentid": 3,      "description": "999",      "catelist": []     },     {      "goodscateid": 10,      "name": "factorybean",      "parentid": 3,      "description": "000",      "catelist": []     }    ]   },   {    "goodscateid": 4,    "name": "struts",    "parentid": 1,    "description": "444",    "catelist": []   }  ] }, {  "goodscateid": 5,  "name": "jdbc",  "parentid": 0,  "description": "555",  "catelist": [   {    "goodscateid": 6,    "name": "hibernate",    "parentid": 5,    "description": "666",    "catelist": []   },   {    "goodscateid": 7,    "name": "mybatis",    "parentid": 5,    "description": "777",    "catelist": []   },   {    "goodscateid": 8,    "name": "jdbctemplate",    "parentid": 5,    "description": "888",    "catelist": []   }  ] }]

public class Dept { private Integer id; private String deptName; private String locAdd; private List<Emp> emps

@JsonIgnoreProperties("dept")public class Emp { private Integer id; private String name; private Dept dept;

public interface DeptMapper { public Dept getDeptById(Integer id);}

public interface EmpMapper { public Emp getEmpByDeptId(Integer deptId); }

<mapper namespace="com.bscc.mapper.DeptMapper"> <resultMap id="DeptResultMap" type="com.bscc.beans.Dept"> <id property="id" column="id"/> <result property="deptName" column="deptName"/> <result property="locAdd" column="locAdd"/> <!-- private List<Emp> emps; column="id"写被集合对象主键，select按照外键键查询，通过deptid查出emp给dept-->  <collection property="emps" column="id" ofType="Emp" select="com.bscc.mapper.EmpMapper.getEmpByDeptId"/> </resultMap> <select id="getDeptById" parameterType="Integer" resultMap="DeptResultMap">  select * from tbl_dept where id=#{id} </select></mapper>

<mapper namespace="com.bscc.mapper.EmpMapper"> <resultMap id="EmpResultMap" type="com.bscc.beans.Emp"> <id property="id" column="id"/> <result property="name" column="name"/> </resultMap> <select id="getEmpByDeptId" parameterType="Integer" resultMap="EmpResultMap"> select * from tbl_emp where deptId=#{deptId} </select></mapper>

@RequestMapping("/getDeptById") @ResponseBody public Dept getDeptById() {  Dept deptById = deptMapper.getDeptById(1);  return deptById; }