The default behavior is to load ‘property values eagerly’ and to load ‘collections lazily’. Contrary to what you might remember if you have used plain Hibernate 2 (mapping files) before, where all references (including collections) are loaded eagerly by default.
A common mistake by beginners, when designing entity models, is to try to make all associations bidirectional. Remember that associations that are not a natural part of the object model should not be forced into it. Hibernate Query Language (HQL) often proves a more natural way to access the required information when needed.
Note that “`mappedBy`” is purely about how the foreign key relationships between entities are saved. It has nothing to do with saving the entities themselves using cascade functionality.
如果这一切看起来都令人困惑，请记住**关联所有权仅与数据库**中外键的管理有关。 我建议您阅读之前的教程，讨论“[**一对一映射**](//howtodoinjava.com/hibernate/hibernate-one-to-one-mapping-using-annotations/"Hibernate one-to-one mapping using annotations") ”，“ [**一对多映射**](//howtodoinjava.com/hibernate/hibernate-one-to-many-mapping-using-annotations/"Hibernate one-to-many mapping using annotations") ”和“ [**多对多映射**](//howtodoinjava.com/hibernate/hibernate-many-to-many-mapping-using-annotations/"Hibernate many-to-many mapping using annotations")”的详细信息。 他们将帮助您建立更强大的概念。
如果这一切看起来都令人困惑，请记住**关联所有权仅与数据库**中外键的管理有关。 我建议您阅读之前的教程，讨论“[**一对一映射**](//howtodoinjava.com/hibernate/hibernate-one-to-one-mapping-using-annotations/"Hibernate one-to-one mapping using annotations")”，“[**一对多映射**](//howtodoinjava.com/hibernate/hibernate-one-to-many-mapping-using-annotations/"Hibernate one-to-many mapping using annotations")”和“[**多对多映射**](//howtodoinjava.com/hibernate/hibernate-many-to-many-mapping-using-annotations/"Hibernate many-to-many mapping using annotations")”的详细信息。 他们将帮助您建立更强大的概念。
如果您要构建的缓存非常大，则最好在文件系统中构建它（例如 Windows 中的 C 驱动器）。 这将防止 Hiberate 状态在每次重新启动应用时建立高速缓存。 同样，[二级缓存提取规则](//howtodoinjava.com/hibernate/how-hibernate-second-level-cache-works/"How hibernate second level cache works?")仍然适用。
但是，如果是多列主键，则必须创建一个代表该主键的类。 当然，它不需要自己的主键，但它必须是公共类，必须具有默认构造函数，必须可序列化，并且必须 **[实现 hashCode()和 equals()方法](//howtodoinjava.com/java/related-concepts/working-with-hashcode-and-equals-methods-in-java/ "Working with hashCode and equals methods in java")** ，以允许 Hibernate 代码测试主键冲突。
但是，如果是多列主键，则必须创建一个代表该主键的类。 当然，它不需要自己的主键，但它必须是公共类，必须具有默认构造函数，必须可序列化，并且必须 [**实现 hashCode()和 equals()方法**](//howtodoinjava.com/java/related-concepts/working-with-hashcode-and-equals-methods-in-java/"Working with hashCode and equals methods in java") ，以允许 Hibernate 代码测试主键冲突。
一旦创建了此主键类，就可以使用以下三种策略：
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@@ -328,7 +328,7 @@ public class EmployeeEntity implements Serializable{
插件 **[maven-compiler-plugin](//howtodoinjava.com/maven/solved-java-compiler-level-does-not-match-the-version-of-the-installed-java-project-facet/ "Solved: Java compiler level does not match the version of the installed Java project facet")** 用于帮助编译代码并使用特定的 JDK 版本进行编译。
插件 [**maven-compiler-plugin**](//howtodoinjava.com/maven/solved-java-compiler-level-does-not-match-the-version-of-the-installed-java-project-facet/"Solved: Java compiler level does not match the version of the installed Java project facet") 用于帮助编译代码并使用特定的 JDK 版本进行编译。
PowerMock currently extends the EasyMock and Mockito mocking frameworks. Depending on which extension is preferred, the syntax to write any unit test differs slightly. In this tutorial, I am using PowerMock with Mockito.
The jqXHR objects returned by $.ajax() implement the Promise interface. The object has all the properties, methods, and behavior of a **[Promise](https://api.jquery.com/deferred.promise/)**.
The jqXHR objects returned by $.ajax() implement the Promise interface. The object has all the properties, methods, and behavior of a [**Promise**](https://api.jquery.com/deferred.promise/).
jQuery 深度克隆意味着独立更改原始对象或克隆对象不会对其他对象产生影响。 换句话说，两个对象（原始对象和克隆对象）都彼此完全独立。 您可以在对象克隆 的 **[指南中阅读有关克隆的更多信息。](//howtodoinjava.com/java/cloning/a-guide-to-object-cloning-in-java/ "A guide to object cloning in java")**
jQuery 深度克隆意味着独立更改原始对象或克隆对象不会对其他对象产生影响。 换句话说，两个对象（原始对象和克隆对象）都彼此完全独立。 您可以在对象克隆 的 [**指南中阅读有关克隆的更多信息。**](//howtodoinjava.com/java/cloning/a-guide-to-object-cloning-in-java/"A guide to object cloning in java")
**阅读更多：[按键事件和击键事件之间的差异](//howtodoinjava.com/2013/12/20/jquery-keyup-function-demo/ "jQuery: difference between keypress and keydown events")** 和 **[检测 ENTER 键](//howtodoinjava.com/scripting/jquery-detect-if-enter-key-is-pressed/ "jQuery: Detect if ENTER key is pressed")**
**阅读更多：[按键事件和击键事件之间的差异](//howtodoinjava.com/2013/12/20/jquery-keyup-function-demo/ "jQuery: difference between keypress and keydown events")** 和 [**检测 ENTER 键**](//howtodoinjava.com/scripting/jquery-detect-if-enter-key-is-pressed/"jQuery: Detect if ENTER key is pressed")
MongoDB shines because of its ease of use, whether a developer is using it in a large-scale application that spans hundreds or thousands of nodes, or in a single-server application that has no need for scale.
