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                # DBMS 中的分層模型 > 原文: [https://beginnersbook.com/2015/04/hierarchical-model-in-dbms/](https://beginnersbook.com/2015/04/hierarchical-model-in-dbms/) 在**分層模型**中,數據被組織成樹狀結構,每個記錄具有一個父記錄和許多子記錄。該模型的主要缺點是,節點之間只能有一對多的關系。 **注意:現在很少使用分層模型。** **樣本層次模型圖**: 讓我們說我們有一些學生和一些課程,一個課程只能分配給一個學生,但是學生可以選修任意數量的課程,這樣這種關系就變成了一對多。 ![Hierarchical_Model_Diagram](https://img.kancloud.cn/8b/b4/8bb49dda37c5ec182014619c1c7a1fea_500x500.jpg) **表示為關系表的分層數據示例:**上述分層模型可以表示為關系表,如下所示: `Student`表: | `Stu_Id` | `Stu_Name` | `Stu_Age` | | --- | --- | --- | | 123 | Steve | 29 | | 367 | Chaitanya | 27 | | 234 | Ajeet | 28 | `Course`表: | `COURSE_ID` | `COURSE_NAME` | `Stu_Id` | | --- | --- | --- | | C01 | COBOL | 123 | | C21 | Java | 367 | | C22 | Perl | 367 | | C33 | JQuery | 234 |
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