JPA - How to select from a database function? - spring

Question

I have the following SQL query in T-SQL:
SELECT a.ReportDate,
a.Value,
a.Quantity,
a.ID,
a.Code
FROM AQF.fCalc(#data) a
#data is a varbinary. I'm trying to replicate this query using JPA. (I'm actually using Spring Data JPA 1.10.2.) I have the following defined in MyRepository:
#Query("SELECT a "
+ "FROM function('AQF.fCalc', :data) a "
)
List<MyClass> getCalcData(#Param("data") byte[] data);
MyClass is as follows:
#Entity
#Data // using lombok to create setters, getters, etc.
public class MyClass {
#Id
private Long id;
private Date reportDate;
private BigDecimal value;
private BigDecimal quantity;
private String code;
}
When I call getCalcData, I receive the following error:
antlr.NoViableAltException: unexpected token: function
at org.hibernate.hql.internal.antlr.HqlBaseParser.fromRange(HqlBaseParser.java:1501) [hibernate-core-5.0.9.Final.jar:5.0.9.Final]...
How can I call the function AQF.fCalc (and pass in the byte array) using JPA?
Update 1
I've now tried using a native query too, but now I get an error stating:
java.sql.SQLException: An error occurred while getting new row from user defined Table Valued Function :
System.Xml.XmlException: Unexpected end of file has occurred. The following elements are not closed: Data, Report. Line 24, position 804.
Here's the test code for the native query in MyRepository:
#Query(value = "SELECT a.code "
+ "FROM AQF.fCalc(?1) a",
nativeQuery = true)
List<String> getCalcData(byte[] data);
Update 2
I was able to resolve the error noted in "Update 1" above. The byte array of data in the getCalcData was corrupted. Once I resolved that issue, the error no longer appeared. So, now I can run as a native query. However, I would still like to know how to use JPQL to make this function call.

Answer 1

You can use StoredProcedureQuery. From the javadoc
Interface used to control stored procedure query execution.
Refer this sample code.
Assume your SQL function name is sales_tax in this example.
EntityManager em = factory.createEntityManager();
// Create call stored procedure
em.getTransaction().begin();
StoredProcedureQuery storedProcedure = em.createStoredProcedureQuery("sales_tax");
// set parameters
storedProcedure.registerStoredProcedureParameter("subtotal", Double.class, ParameterMode.IN);
storedProcedure.registerStoredProcedureParameter("tax", Double.class, ParameterMode.OUT);
storedProcedure.setParameter("subtotal", 1f);
// execute SP
storedProcedure.execute();
// get result
Double tax = (Double)storedProcedure.getOutputParameterValue("tax");
System.out.println("Tax is: " + tax);
em.getTransaction().commit();
em.close();