IT修真院·坑乎 | Java(后端),CSS(前端),JavaScript(前端),PM(产品经理),UI(交互设计),QA(测试),Android(安卓APP),iOS(苹果APP),OP(运维),Python(后端)日常在线问答学习平台
咨询电话 : 010-59478634
切换导航
首页
我的提问
我的回答
我的点赞
消息通知
个人主页
×
提示
尚未登陆,前往官网登陆?
×
提示
尚未登陆,前往官网登陆?
CSS
JS
Android
IOS
JAVA
OP
PM
UI
QA
求职辅导
Python
运营
动画师
CSS
JS
Android
IOS
JAVA
OP
PM
UI
QA
求职辅导
Python
运营
动画师
所有任务
任务1
任务2
任务3
任务4
任务5
任务6
任务7
任务8
任务9
任务10
任务11
全部
问题
已收录
问题
未收录
问题
没有找到答案,去提问>>>
如何更好的设计表?
0
1
class="cursor-pointer"> 详细描述
设计思想从哪里开始起头,怎么样去选择字段,怎么样去选择类型,已达到更好的效果?
Mybatis的if标签判空会把0判成空
0
1
class="cursor-pointer"> 详细描述
确定参数能够传入Mybatis,但是会把0识别成空导致这条拼接失效,
class="cursor-pointer"> 错误截图
可以看到传入的这个对象是有两个参数 messageReplyWorkId=1, messageReplyId=0 但是动态sql拼接之后只有 Preparing: SELECT * FROM message WHERE message_reply_work_id=? ORDER BY message_create_at DESC
class="cursor-pointer"> 源码
SELECT * FROM message
message_id=#{messageId}
AND message_status=#{messageStatus}
AND message_reply_work_id=#{messageReplyWorkId}
AND message_reply_id=#{messageReplyId}
ORDER BY message_create_at DESC
mapper
public CodeMessageData selectMessage(Work workReceive, Message messageReceive, Integer pn, Integer num) { PageHelper.startPage(pn, num); Work work = new Work(); work.setWorkName(workReceive.getWorkName()); List
workList = workMapper.selectWork(work); if(null==workList||workList.size()==0){ return new CodeMessageData(0,"未找到该作品"); }else{ Message message = new Message(); message.setMessageReplyWorkId(workList.get(0).getWorkId()); message.setMessageReplyId(0L); message.setMessageStatus(messageReceive.getMessageStatus()); List
messageList = messageMapper.selectMessage(message); if (null == messageList || messageList.size() == 0) { return new CodeMessageData(0, "未找到该作品留言"); } else { return new CodeMessageData(1, "查询成功", new PageInfo
(messageList)); } } }
service
@RequestMapping(value = "/SelectMessage", method = RequestMethod.POST) public CodeMessageData selectMessage(Work workReceive, Message messageReceive, Integer pn, Integer num) { if(null!=messageReceive.getMessageStatus()&&(messageReceive.getMessageStatus()!=0&&messageReceive.getMessageStatus()!=1)){ return new CodeMessageData(0,"留言状态错误"); }else if(null==workReceive.getWorkName()||workReceive.getWorkName()==""){ return new CodeMessageData(0,"留言所属作品名错误"); }else if (null==pn||pn<=0||null==num||num<=0) { return new CodeMessageData(0, "页码错误"); }else{ return messageService.selectMessage(workReceive,messageReceive,pn,num); } }
controller
nginx配置反向代理的路径问题
0
1
class="cursor-pointer"> 详细描述
我想要代理nginx的项目名,但是直接写proxy_pass http://localhost:8080/clxs;代理不了,一直报错页面多次重定向
如何在实现保存排序的需求同时保证逻辑上不会出错
0
1
class="cursor-pointer"> 详细描述
确定保存排序的需求在对应数据库表中建立字段,使用批量更新该字段实现。 字段不能建立唯一索引,不可设置主键,因为需要实现值的交换; 字段逻辑上不能重复,需要在保存新的排序之后增加一个检测是否重复,若重复回退操作(需预先存入一个集合listBackup); 当新增一条数据时,如何增加该字段,确保删除一条字段后再新增,字段逻辑不会出错; 使用foreach遍历时需检查是否数据为null,抛出异常且不执行数据。 主要是这些思路,但是这样实现确实很复杂,虽然已经实现,但是寻求更简单的实现方法。
class="cursor-pointer"> 源码
//保存排序 @RequestMapping(value = "/UpdateOrderBy",method = RequestMethod.POST) public CodeMessageDate updateOrderBy(@RequestBody List
workCollections){ if(null==workCollections||workCollections.size()==0){ return new CodeMessageDate(0,"无传入数据"); }else{ List
listBackup = new ArrayList<>(); List
list = new ArrayList<>(); for(WorkCollection collection:workCollections){ WorkCollection workCollectionBackup = new WorkCollection(); WorkCollection workCollection = new WorkCollection(); workCollection.setCollectionId(collection.getCollectionId()); if(null==workCollectionService.selectCollection(workCollection)){ return new CodeMessageDate(0,"未找到该条数据",workCollection); }else if(null==collection.getCollectionOrderBy()||collection.getCollectionOrderBy()<=0) { return new CodeMessageDate(0, "未找到排序数据",workCollection); }else { workCollectionBackup.setCollectionId(workCollectionService.selectCollection(workCollection).getCollectionId()); workCollectionBackup.setCollectionOrderBy(workCollectionService.selectCollection(workCollection).getCollectionOrderBy()); listBackup.add(workCollectionBackup); workCollection.setCollectionOrderBy(collection.getCollectionOrderBy()); list.add(workCollection); } } workCollectionService.updateOrderBy(list); if (null==workCollectionService.selectCollectionOrderBy()||workCollectionService.selectCollectionOrderBy().size()==0){ return new CodeMessageDate(1,"保存排序成功"); }else{ workCollectionService.updateOrderBy(listBackup); return new CodeMessageDate(0,"排序数据错误,操作已回退"); } }
controller层
//保存排序 int updateOrderBy(@Param(value = "list")List
list);
dao层mapper接口
select collection_order_by from work_collection order by collection_order_by desc
update work_collection set collection_order_by=#{workCollection.collectionOrderBy} where collection_id=#{workCollection.collectionId}
select * from work_collection where collection_id=#{collectionId}
select collection_order_by from work_collection group by collection_order_by having count(*)>1
mapper.xml
//新增作品集 int insertCollection(WorkCollection workCollection); //保存排序-通过id查询作品集 WorkCollection selectCollection(WorkCollection workCollection); //保存排序-查询order_by字段是否有重复 List
selectCollectionOrderBy(); //保存排序 int updateOrderBy(List
list);
service接口
//保存排序-通过id查询作品集 public WorkCollection selectCollection(WorkCollection workCollection){ return workCollectionMapper.selectCollection(workCollection); } //保存排序-查询order_by字段是否有重复 public List
selectCollectionOrderBy(){ return workCollectionMapper.selectCollectionOrderBy(); } //保存排序 public int updateOrderBy(List
list){ return workCollectionMapper.updateOrderBy(list);}
service实现
关于linux当中配置tomcat,nginx等等的端口问题
0
1
class="cursor-pointer"> 详细描述
我的linux服务器只能监听80端口,每次如果修改为别的端口,都是报错,启动不了,这个地方很疑惑,难道我以前修改过linux,把系统设定为只能监听80端口吗?
首页
<
12
13
14
15
16
17
末页
去第
页
确定
Copyright ©2015 北京葡萄藤信息技术有限公司 All Rights Reserved | 京ICP备15035574号-1
6
5
10