Automatically Add a Prefix to Column Names for @Embeddable Classes
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_T
onto the same column (i.e. startTime.sec
and stopTime.sec
both try to map to the colum sec
, causing an error).
@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开发者_JS百科 per-field basis. Does Hibernate have this capability, or is there any other reasonable work-around?
Try setting the property hibernate.ejb.naming_strategy
to org.hibernate.cfg.DefaultComponentSafeNamingStrategy
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:
spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyComponentPathImpl
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
Another way to solve the problem is by using @AttributeOverrides and @AttributeOverride annotations. In your example the Time_T.sec
property is mapped to sec
column. You could map ExampleClass like this:
@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_sec
and stopTime.sec <=> sec
. Of course you could use annotations to create a more meaningful name for stopTipe.sec
column.
spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyComponentPathImpl spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
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