java 自动为@Embeddable 类的列名添加前缀
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Automatically Add a Prefix to Column Names for @Embeddable Classes
提问by VeeArr
I am developing a project in which I am persisting some POJOs by adding Hibernate annotations. One problem I am running into is that code like this fails, as Hibernate tries to map the sub-fields within the Time_Tonto the same column (i.e. startTime.secand stopTime.secboth try to map to the colum sec, causing an error).
我正在开发一个项目，在该项目中我通过添加 Hibernate 注释来保留一些 POJO。我遇到的一个问题是，像这样的代码失败了，因为 Hibernate 尝试将 内的子字段映射Time_T到同一列（即startTime.sec，stopTime.sec两者都尝试映射到 colum sec，导致错误）。
@Entity
public class ExampleClass
{
@Id
long eventId;
Time_T startTime;
Time_T stopTime;
}
@Embeddable
public class Time_T
{
int sec;
int nsec;
}
As there will be many occurrences like this throughout the system, it would be nice if there was an option to automatically append a prefix to the column name (e.g. make the columns be startTime_sec, startTime_nsec, stopTime_sec, stopTime_nsec), without having to apply overrides on a per-field basis. Does Hibernate have this capability, or is there any other reasonable work-around?
由于在整个系统中会出现很多这样的情况，如果有一个选项可以自动将前缀附加到列名（例如，使列成为startTime_sec, startTime_nsec, stopTime_sec, stopTime_nsec），而不必对每个应用程序进行覆盖，那就太好了。场基础。Hibernate 是否具有此功能，或者是否有其他合理的解决方法？
采纳答案by Bozho
Try setting the property hibernate.ejb.naming_strategyto org.hibernate.cfg.DefaultComponentSafeNamingStrategy
尝试将属性设置hibernate.ejb.naming_strategy为org.hibernate.cfg.DefaultComponentSafeNamingStrategy
回答by Farrukh Najmi
In my case with org.hibernate:hibernate-core:5.0.12.Final and org.springframework.boot:spring-boot-starter-data-jpa:1.5.2.RELEASE I had to do the following properties in my application.properties file:
在我使用 org.hibernate:hibernate-core:5.0.12.Final 和 org.springframework.boot:spring-boot-starter-data-jpa:1.5.2.RELEASE 的情况下，我必须在我的应用程序中执行以下属性。属性文件：
spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyComponentPathImpl
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
回答by Matheus Moreira
Another way to solve the problem is by using @AttributeOverrides and @AttributeOverride annotations. In your example the Time_T.secproperty is mapped to seccolumn. You could map ExampleClass like this:
另一种解决问题的方法是使用@AttributeOverrides 和@AttributeOverride 注释。在您的示例中，该Time_T.sec属性映射到sec列。你可以像这样映射 ExampleClass：
@Entity
public class ExampleClass {
@Id
long eventId;
@AttributeOverrides(
@AttributeOverride(name = "sec", column = @Column(name = "start_sec"))
)
Time_T startTime;
Time_T stopTime;
}
The result mapping is startTime.sec <=> start_secand stopTime.sec <=> sec. Of course you could use annotations to create a more meaningful name for stopTipe.seccolumn.
结果映射是startTime.sec <=> start_sec和stopTime.sec <=> sec。当然，您可以使用注释为stopTipe.sec列创建更有意义的名称。
回答by Prabir Palai
spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyComponentPathImpl spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyComponentPathImpl spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
