如何使用 Hibernate (EntityManager) 或 JPA 调用 Oracle 函数或过程 [英] How to call Oracle Function or Procedure using Hibernate (EntityManager) or JPA

问题描述

我有一个返回 sys-refcursor 的 Oracle 函数，当我使用 Hibernate 调用该函数时，出现以下异常.

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)

我该如何解决这个问题?

How can I resolve this?

Oracle 函数

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;

我的实体类

@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")

在 DAO 中

    @Override
        public void findEmployees(QueryData data,
                String empName) {

        List query = (List) entityManager.createNamedQuery("getFunc")
                         .setParameter("empName", empName)
                         .getSingleResult();
                data.setResult(query);
}

推荐答案

可以通过以下方式使用 EntityManager 调用 Oracle 函数或存储过程.

Oracle function or a stored procedure can be called using EntityManager in the following manner.

对于 Oracle 函数

创建一个返回类型为 sys_refcursor 的函数

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;

在实体类中，定义函数为

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") })

对于 Oracle 存储过程

以sys_refcursor作为第一个OUT参数创建过程

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||'%');

在实体类中将过程定义为

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") })

最后在 DAO 类中调用函数或过程为

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(); 

谢谢

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