I have an Oracle function which return sys-refcursor and when I call this function using Hibernate, I am getting the following exception.
Hibernate: { ? = call my_function(?) }
org.hibernate.exception.GenericJDBCException: could not execute query
javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: could not execute query
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1360)
at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1288)
at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:313)
How can I resolve this?
Oracle function
create or replace
FUNCTION my_function(p_val IN varchar2)
RETURN SYS_REFCURSOR
AS
my_cursor SYS_REFCURSOR;
BEGIN
OPEN my_cursor FOR SELECT emp_name FROM employees
WHERE lower(emp_name) like lower(p_val||'%');
RETURN my_cursor;
END;
My Entity class
@Entity
@javax.persistence.NamedNativeQuery(name = "getFunc", query =
"{ ? = call my_function(:empName) }",
resultClass = Employee.class, hints =
{ @javax.persistence.QueryHint(name = "org.hibernate.callable", value = "true") })
@Table(name = "EMPLOYEES")
and in DAO
@Override
public void findEmployees(QueryData data,
String empName) {
List query = (List) entityManager.createNamedQuery("getFunc")
.setParameter("empName", empName)
.getSingleResult();
data.setResult(query);
}
Oracle function or a stored procedure can be called using EntityManager in the following manner.
For Oracle Function
Create a function with sys_refcursor as return type
CREATE OR REPLACE FUNCTION my_function
(p_val IN varchar2)
RETURN SYS_REFCURSOR
AS
my_cursor SYS_REFCURSOR;
BEGIN
OPEN my_cursor FOR SELECT emp_name FROM employees
WHERE lower(emp_name) like lower(p_val||'%');
RETURN my_cursor;
END;
In Entity class, define function as
@javax.persistence.NamedNativeQuery(name = "getFunc", query = "{? = call
my_function(:empName) }", resultClass = Employee.class, hints = {
@javax.persistence.QueryHint(name = "org.hibernate.callable", value = "true") })
For Oracle Stored Procedure
Create procedure with sys_refcursor
as first OUT parameter
CREATE OR REPLACE PROCEDURE myProcedure(p_cursor out sys_refcursor,
p_val in varchar2
)
AS
BEGIN
OPEN o_cursor FOR
SELECT emp_name
FROM employees
WHERE LOWER (emp_name) LIKE lower(p_val||'%');
In Entity class define procedure as
@javax.persistence.NamedNativeQuery(name = "getProc", query = "{ call
my_procedure(?,:empName) }", resultClass = Employee.class, hints = {
@javax.persistence.QueryHint(name = "org.hibernate.callable", value = "true") })
and finally in DAO class call function or procedure as
Query query = entityManager.createNamedQuery("getFunc"); // if procedure then getProc
query.setParameter("empName","smith");
query.getResultList();
Thanks