递归查询

select id,name from sys_dept where pids like '%1067246875800000065%' and del_flag = 0

select id,name from sys_dept where pid ='1067246875800000065' and del_flag = 0

/**
 * getChildSubDeptIdList
 * @return
 */
@GetMapping("getChildSubDeptIdList")
@ApiOperation("getChildSubDeptIdList")
public Result<List<Long>> getChildSubDeptIdList(){
    List<Long> idList =new ArrayList<>();
    List<Long> data = sysDeptService.getChildSubDeptIdList(1067246875800000065L,idList);
    return new Result<List<Long>>().ok(data);
}

/**
 *
 * @param id   部门ID
 * @return
 */
@Override
public List<Long> getChildSubDeptIdList(Long id,List<Long> idList) {
    List<Long> deptIdList = baseDao.getChildSubDeptIdList(id);
    for (int i=0;i<deptIdList.size();i++){
        Long deptId= deptIdList.get(i);
        idList.add(deptId);
        getChildSubDeptIdList(deptId,idList);
    }
    deptIdList.add(id);
    return idList;
}

/**
 * 根据部门ID，获取所有子部门ID列表
 * @param id   部门ID
 */
List<Long> getChildSubDeptIdList(Long id);

<select id="getChildSubDeptIdList" resultType="long">
    select id from sys_dept where pid = #{id} and del_flag = 0
</select>


子查询父级

/**
 * getParentPidById
 * @return
 */
@GetMapping("getParentPidById")
@ApiOperation("getParentPidById")
public Result<List<Long>> getParentPidById(){
    List<Long> idList =new ArrayList<>();
    List<Long> data = sysDeptService.getParentPidById(1425390890702680066L,idList);
    return new Result<List<Long>>().ok(data);
}

/**
 * 根据部门ID，获取本部门及父部门ID列
 * @param id
 * @param idList
 * @return
 */
List<Long> getParentPidById(Long id,List<Long> idList);

/**
 * getParentPidById
 * @param id
 * @param idList
 * @return
 */
@Override
public List<Long> getParentPidById(Long id,List<Long> idList) {
    Long deptId = baseDao.getParentPidById(id);
    if (deptId!=null && deptId!=0L){
        idList.add(deptId);
        getParentPidById(deptId,idList);
    }
    return idList;
}

/**
 *  根据部门ID，获取所有父部门ID列表
 * @param id
 * @return
 */
Long getParentPidById(Long id);

<select id="getParentPidById" resultType="long">
    select pid from sys_dept where id = #{id} and del_flag = 0
</select>

/**
 * 获取所有上级部门ID
 * @param pid 上级ID
 */
private String getPidList(Long pid){
    //顶级部门，无上级部门
    if(Constant.DEPT_ROOT.equals(pid)){
        return Constant.DEPT_ROOT + "";
    }

    //所有部门的id、pid列表
    List<SysDeptEntity> deptList = baseDao.getIdAndPidList();

    //list转map
    Map<Long, SysDeptEntity> map = new HashMap<>(deptList.size());
    for(SysDeptEntity entity : deptList){
        map.put(entity.getId(), entity);
    }

    //递归查询所有上级部门ID列表
    List<Long> pidList = new ArrayList<>();
    getPidTree(pid, map, pidList);

    return StringUtils.join(pidList, ",");
}

/**
 * 递归查询
 * @param pid
 * @param map
 * @param pidList
 */
private void getPidTree(Long pid, Map<Long, SysDeptEntity> map, List<Long> pidList) {
    //顶级部门，无上级部门
    if(Constant.DEPT_ROOT.equals(pid)){
        return ;
    }

    //上级部门存在
    SysDeptEntity parent = map.get(pid);
    if(parent != null){
        getPidTree(parent.getPid(), map, pidList);
    }

    pidList.add(pid);
}