mybatis：递归查询，关联查询传入多个参数

需求是：递归查询资源

1.资源类 EntityBaseResource：

public final class EntityBaseResource {
  private Long resID = 0l;

  private String resName = "";

  private String urlPath = "";

  private String parentResID = "";

  private String iconClass = "fa fa-circle-o";

  private short level = 1;

  private String resType = "";

  private String permission = "";

  private String belongTo = "";

  private String isPublished = "";

  private short seq = 1;

  private String isValid = "1";

  // 子资源
  private List<EntityBaseResource> children;

  public final Long getResID() {
    return resID;
  }

  public final void setResID(Long resID) {
    this.resID = resID;
  }

  public final String getResName() {
    return resName;
  }

  public final void setResName(String resName) {
    this.resName = resName == null ? Constant.BLANK : resName.trim();
  }

  public final String getUrlPath() {
    return urlPath;
  }

  public final void setUrlPath(String urlPath) {
    this.urlPath = urlPath == null ? Constant.BLANK : urlPath.trim();
  }

  public final String getParentResID() {
    return parentResID;
  }

  public final void setParentResID(String parentResID) {
    this.parentResID = parentResID == null ? Constant.BLANK : parentResID.trim();
  }

  public final String getIconClass() {
    return iconClass;
  }

  public final void setIconClass(String iconClass) {
    this.iconClass = iconClass == null ? Constant.BLANK : iconClass.trim();
  }

//省略get/set方法

2.DAO

import java.util.List;

import org.apache.ibatis.annotations.Param;

import com.csget.entity.base.EntityBaseResource;

public interface DaoBaseResource {
    int deleteByPrimaryKey(Long resID);

    int insert(EntityBaseResource record);

    EntityBaseResource selectByPrimaryKey(Long resID);

    List<EntityBaseResource> selectRecursionRes(@Param("resID") Long resID, @Param("belongTo") String belongTo);

    int updateByPrimaryKey(EntityBaseResource record);
}

<?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.csget.dao.base.DaoBaseResource">

    <!-- 基础属性 -->
    <resultMap id="BaseResultMap" type="com.csget.entity.base.EntityBaseResource">
        <id column="resID" jdbcType="BIGINT" property="resID" />
        <result column="resName" jdbcType="VARCHAR" property="resName" />
        <result column="urlPath" jdbcType="VARCHAR" property="urlPath" />
        <result column="parentResID" jdbcType="VARCHAR"
            property="parentResID" />
        <result column="iconClass" jdbcType="VARCHAR"
            property="iconClass" />
        <result column="level" jdbcType="TINYINT" property="level" />
        <result column="resType" jdbcType="VARCHAR" property="resType" />
        <result column="permission" jdbcType="VARCHAR"
            property="permission" />
        <result column="seq" jdbcType="TINYINT" property="seq" />
        <result column="isValid" jdbcType="CHAR" property="isValid" />
    </resultMap>
    <!-- 递归资源，继承基础属性 -->
    <resultMap id="resAll" extends="BaseResultMap" type="com.csget.entity.base.EntityBaseResource">
        <collection property="children" ofType="resAll"
            column="{resID=resID,belongTo=belongTo}" select="selectRecursionRes" />
    </resultMap>

    <!-- 递归资源 -->
    <select id="selectRecursionRes" resultMap="resAll">
        SELECT resID, resName, urlPath, parentResID, iconClass, belongTo FROM t_base_resource
        WHERE parentResID=#{resID} and belongTo=#{belongTo} and isValid='1' ORDER BY seq ASC
    </select>
</mapper>

DAO在调用时，通过注解传入参数

递归查询时多个参数参数，会自动调用查询结果中的字段值

同时递归查询，resultMap采用的继承属性 ，这样可以避免一些不必要的查询，例如如果你只需要查询一条记录，不需要查询它下面的子集。