何时在hibernate中使用DiscriminatorValue注解 [英] When to use DiscriminatorValue annotation in hibernate

问题描述

在hibernate中使用DiscriminatorValue注解的最佳场景是什么？什么时候是最好的？

概念最多：

http://docs.oracle.com/javaee/6/tutorial/doc/bnbqn.html

http://www.javaworld.com/javaworld/jw-01-2008 /jw-01-jpa1.html?page=6

要理解鉴别器，首先您必须了解继承策略：SINGLE_TABLE，JOINED，TABLE_PER_CLASS。

Discriminator常用于SINGLE_TABLE继承，因为您需要一列来标识记录的类型。

示例：你有一个班级学生和两个小班：好学生和坏学生。 Good和BadStudent数据都将存储在1个表中，但我们当然需要知道类型，这是DiscriminatorColumn的用途。请参阅上面张贴的链接。

What and when is the best scenario to use DiscriminatorValue annotation in hibernate?

解决方案

These 2 links help me understand the inheritance concept the most:

http://docs.oracle.com/javaee/6/tutorial/doc/bnbqn.html

http://www.javaworld.com/javaworld/jw-01-2008/jw-01-jpa1.html?page=6

To understand discriminator, first you must understand the inheritance strategies: SINGLE_TABLE, JOINED, TABLE_PER_CLASS.

Discriminator is commonly used in SINGLE_TABLE inheritance because you need a column to identify the type of the record.

Example: You have a class Student and 2 sub-classes: GoodStudent and BadStudent. Both Good and BadStudent data will be stored in 1 table, but of course we need to know the type and that's when DiscriminatorColumn will come in. See the links I posted above.

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