Mapping enum types with Hibernate Annotations
I have an enum开发者_如何转开发 type on my Java model which I'd like to map to a table on the database. I'm working with Hibernate Annotations and I don't know how to do that. Since the answers I search were rather old, I wonder which way is the best?
Thanks in advance
Do you need something else than the @Enumerated
annotation? For example, the following enum:
public enum MyEnum {
VALUE1, VALUE2;
}
Could be used and annotated like this:
private MyEnum myEnum;
@Column(name="myenum")
@Enumerated(EnumType.ORDINAL)
public MyEnum getMyEnum() {
return myEnum
}
You can specify how the enum should be persisted in the database with the EnumType
enum property of the @Enumerated
annotation. EnumType.ORDINAL
specifies that the enum will be persisted as an integer value. Here, myEnum
set to VALUE1
would be persisted as 0, VALUE2
as 1, etc.
The alternative is to use EnumType.STRING
to specify that the enum will be persisted using the name of the enum value that the field is set to. So, applied to the previous example, setting the field myEnum
to MyEnum.VALUE1
will persist as VALUE1
, etc.
public enum OrderStatus {
ORDER_CREATED,ORDER_COMPLETED,ORDER_CANCELLED
}
@Entity
public class PurchaseOrder {
@Enumerated(EnumType.STRING)
private OrderStatus orderStatus;
}
Here OrderStatus
is a referenced datatype(java object) , now you want to persist this OrderStatus
in database, but its not possible to directly persist a java object into database
now here @Enumerated(EnumType.STRING)
comes into picture to convert that OrderStatus
java object into String so that it can be persisted into DB.
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