unexpected token: '<function_name>' error when using hibernate, JPQL and postgres function

Question

I'm using PostgreSQL 9.6 with Hibernate 5.4.8 , Java 8 and Spring framework. I need to call a postgres function

CREATE OR REPLACE FUNCTION function_that_return_array(givenIds character varying(255)) RETURNS int[] AS
'
BEGIN
    RETURN string_to_array($1,'','');
END
' LANGUAGE plpgsql;

within JPQL query

private static final String JPQL_QUERY =
    " SELECT NEW com.package.CustomProjection( " +
    "  e.id, " +
    "  e.value " +
    " ) " +
    " FROM SomeEntity e " +
    " WHERE e.id = ANY(function_that_return_array(:ids))";

and using entity manager:

@Autowired
private final EntityManager entityManager;

// ...

this.entityManager.createQuery(JPQL_QUERY, CustomProjection.class)
                .setParameter("ids", "1,2,3")
                .getResultList();

and it results in following exception:

antlr.NoViableAltException: unexpected token: function_that_return_array
    at org.hibernate.hql.internal.antlr.HqlBaseParser.selectFrom(HqlBaseParser.java:1055) [hibernate-core-5.4.8.Final.jar:5.4.8.Final]
    at org.hibernate.hql.internal.antlr.HqlBaseParser.queryRule(HqlBaseParser.java:748) [hibernate-core-5.4.8.Final.jar:5.4.8.Final]
    at org.hibernate.hql.internal.antlr.HqlBaseParser.subQuery(HqlBaseParser.java:3910) [hibernate-core-5.4.8.Final.jar:5.4.8.Final]
    at org.hibernate.hql.internal.antlr.HqlBaseParser.quantifiedExpression(HqlBaseParser.java:3515) [hibernate-core-5.4.8.Final.jar:5.4.8.Final]
    at org.hibernate.hql.internal.antlr.HqlBaseParser.unaryExpression(HqlBaseParser.java:3373) [hibernate-core-5.4.8.Final.jar:5.4.8.Final]
...
antlr.MismatchedTokenException: expecting EOF, found ')'
    at antlr.Parser.match(Parser.java:211) ~[antlr-2.7.7.jar:?]
    at org.hibernate.hql.internal.antlr.HqlBaseParser.statement(HqlBaseParser.java:215) [hibernate-core-5.4.8.Final.jar:5.4.8.Final]

The above example is very simplified but it correctly represents the production problem. When I call above function in native SQL it works perfectly:

select *
from some_entity e 
where e.id = ANY(function_that_return_array('1,2,3,4'))

Does anyone know how to call a postgres function within JPQL and Hibernate or can point me out what I am doing wrong? I was reading many articles like this one , SO questions and I was trying dozens of combinations but with no success so far. Thanks in advance.

Answer 1

In Hibernate dialect you cannot call directly not registered custom database functions. The exception in clear, hibernate knows nothing about your function:

unexpected token: function_that_return_array

You have two options here:

1. Call your function by generic mechanism for custom functions:

use

function('function_that_return_array', '1,2,3,4')

instead of

function_that_return_array('1,2,3,4')

2. Second option is to register your function: https://docs.jboss.org/hibernate/orm/5.1/javadocs/org/hibernate/dialect/Dialect.html#registerFunction-java.lang.String-org.hibernate.dialect.function.SQLFunction-

Example:

public class MyDialect extends PostgreSQLXXDialect {
    public MyDialect() {
        super();
        registerFunction("function_that_return_array", new StandardSQLFunction("function_that_return_array"));
    }
}