實(shí)體類為什么用Integer而不是int呢
//主鍵ID private??areaId; //名稱 private?String?areaName; //權(quán)重(越大越排前顯示) private?priority; //創(chuàng)建時(shí)間 private?Date?createTime; //更新時(shí)間 private?Date?lastEditTime;
什么叫為了以后非空校驗(yàn)?
//主鍵ID private??areaId; //名稱 private?String?areaName; //權(quán)重(越大越排前顯示) private?priority; //創(chuàng)建時(shí)間 private?Date?createTime; //更新時(shí)間 private?Date?lastEditTime;
什么叫為了以后非空校驗(yàn)?
2018-05-27
舉報(bào)
2018-05-28
因?yàn)閕nt如果設(shè)為空的話默認(rèn)為0而Integer為Null.. Null對(duì)于程序來說比較好控制,可以做空值判斷以及對(duì)數(shù)據(jù)做統(tǒng)一處理