how to use postgresql array_agg function in JpaRepository spring boot? - spring-boot

Question

I have created new spring boot project with postgresql .I like to use posgressql array_agg(ex:get all department) using JPA Repository native query but its getting some error in blow posted. I have tried some alter solution but cant able to get expected data.
Error :
org.springframework.orm.jpa.JpaSystemException: No Dialect mapping for JDBC type: 2003;
nested exception is org.hibernate.MappingException: No Dialect mapping for JDBC type: 2003
Expected : Should get array or list of data
#Repository
public interface PostGroupRepository extends JpaRepository<PostGroup, Integer> {
#Query(value = "SELECT array_agg(department) FROM boxinfo;", nativeQuery = true)
public Object[] getDept();
}

Answer 1

First solution is to use below dependency:
<dependency>
<groupId>com.vladmihalcea</groupId>
<artifactId>hibernate-types-52</artifactId>
<version>2.11.1</version>
</dependency>
he has custom types already written and register that in the custom dialect like below
public class CustomPostgreDialect extends PostgreSQL10Dialect {
public CustomPostgreDialect() {
super();
this.registerHibernateType(2003, StringArrayType.class.getName());
}
}
And use this dialect as the hibernate dialect in application.yaml or application.properties of spring boot.
spring.jpa.properties.hibernate.dialect: <packageName>.CustomPostgreDialect
Second solution is to write the custom type yourself and register it in the dialect as shown above, if you don't want to use dependency.