JPA Criteria API group_concat usage

by

I figured out how to do this with Hibernate-jpa-mysql:

1.) created a GroupConcatFunction class extending org.hibernate.dialect.function.SQLFunction (this is for single column group_concat for now)

public class GroupConcatFunction implements SQLFunction {

@Override
public boolean hasArguments() {
    return true;
}

@Override
public boolean hasParenthesesIfNoArguments() {
    return true;
}

@Override
public Type getReturnType(Type firstArgumentType, Mapping mapping)
        throws QueryException {
    return StandardBasicTypes.STRING;
}

@Override
public String render(Type firstArgumentType, List arguments,
        SessionFactoryImplementor factory) throws QueryException {
    if (arguments.size() != 1) {
        throw new QueryException(new IllegalArgumentException(
                "group_concat shoudl have one arg"));
    }
    return "group_concat(" + arguments.get(0) + ")";
}

}

2.) i created the CustomMySql5Dialect class extending org.hibernate.dialect.MySQL5Dialect and registered the group_concat class created in step 1

3.) On the app context, i updated the jpaVendorAdapter to use the CustomMySql5Dialect as the databasePlatform

4.) Finally to use it

criteriaBuilder.function("group_concat", String.class,
        sampleRoot.get("sampleColumnName"))

More Related Contents:

  1. JPA EntityManager: Why use persist() over merge()?
  2. JPA 2.0, Criteria API, Subqueries, In Expressions
  3. When use getOne and findOne methods Spring Data JPA
  4. Create JPA EntityManager without persistence.xml configuration file
  5. Spring Data JPA And NamedEntityGraphs
  6. How to persist JSR-310 types with Spring Data JPA?
  7. Is it possible to output generated SQL using EclipseLink without having to increase log verbosity?
  8. JPA passing list to IN clause in named native query
  9. Spring batch jpaPagingItemReader why some rows are not read?
  10. JPA 2.0 native query results as map
  11. kotlin data class + bean validation jsr 303
  12. JPA transient information lost on create
  13. How do I do a “deep” fetch join in JPQL?
  14. Testing an EJB with JUnit
  15. Spring Data JPA and Querydsl to fetch subset of columns using bean/constructor projection
  16. JPA utf-8 characters not persisted
  17. JPA Query to handle NULL parameter value
  18. How do I count the number of rows returned by subquery?
  19. Mapping many-to-many association table with extra column(s)
  20. What is the meaning of the CascadeType.ALL for a @ManyToOne JPA association
  21. How to generate the JPA entity Metamodel?
  22. Storing a Map using JPA
  23. Hibernate: Automatically creating/updating the db tables based on entity classes
  24. Implementing custom methods of Spring Data repository and exposing them through REST
  25. Why does Hibernate disable INSERT batching when using an IDENTITY identifier generator
  26. Java JPA Class for MATLAB
  27. No Persistence provider for EntityManager named X
  28. Limit number of results in JPQL
  29. Use abstract super class as parameter for Spring data repository
  30. Spring-boot: required a bean named ‘entityManagerFactory’ that could not be found

Leave a Comment