时间：2021-07-01 10:21:17 帮助过：2人阅读
# 表1：对象自述表 people
id:1,name:coolGuy,adress:china
id:2,name:baby,adress:china
# 表1：对象自述表 book
id:1,title:a book,date:2016
id:2,title:a bag,date:2016
id:3,title:apple,date:2016
# 表1：对象自述表 song
id:1,name:rainbow
id:2,name:the sun
# 表2：对象关联表 people_book
bookId:1,peopleId:1
bookId:2,peopleId:1
bookId:3,peopleId:2
# 表2：对象关联表 people_song
songId:1,peopleId:2
songId:2,peopleId:2
# 表3：对象包含表 people_containsObject
peopleId:1,table:people_book
peopleId:2,table:people_book
peopleId:2,table:people_song
无耦合的数据库，3合1结构（或称3层结构）
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