JPA how ensure uniqueness over 2 fields, string and boolean

Question

I want to create an entity containing 2 fields that need to be unique in together. One of the fields is a Boolean:

@Entity
public class SoldToCountry {

    private String countryId;


    private Boolean isInt;
}

For a given String there should never exist more than 2 entries one with isInt:true and the other isInt:false.

I read the doc about @Id but it seems that Boolean is not supported. For me it would also be ok to have a unique constraint spanned over both fields and using a generated id.

What is the best way to get this constraint via JPA?

Have a look at [UniqueConstraint](https://docs.oracle.com/javaee/6/api/javax/persistence/UniqueConstraint.html). — Sebastian, Mar 13 '19 at 14:44
do you want the two fields to be the primary key for the table? or you have another PK, and they are just another constrant on the table? — luca.vercelli, Mar 13 '19 at 14:45

score 1 · Answer 1 · answered Mar 13 '19 at 14:51

1

If your table has really two fields only, and you want they are unique, then they should be the composite PK of the table. Take a look at How to create and handle composite primary key in JPA

If, instead, you have another PK, consider Sebastian's comment.

answered Mar 13 '19 at 14:51

luca.vercelli

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it would be nice to see an example with a Boolean as part of a PK – dermoritz Mar 14 '19 at 08:51
I think there are not problems with booleans in JPA. Provided that your database supports boolean columns. What DB are you using? (I am talking about using @EmbeddedId, not @Id). – luca.vercelli Mar 14 '19 at 08:57
We use Oracle. Thanks i will try. I only read somewhere that only specific bse classes could be part of an id class. – dermoritz Mar 14 '19 at 09:11
I am afraid Oracle has no Boolean datatype. Maybe you should change Java datatype to conform to corresponding Oracle column type. – luca.vercelli Mar 14 '19 at 09:24

JPA how ensure uniqueness over 2 fields, string and boolean

1 Answers1