nhibernate，Oracle中的调用函数，它返回sys refcursor

Question

I am trying to call a function (oracle) using nhibernate that return ref cursor, but i am not successful with the hbm file, can any one please guide me with this.

If i make it like <return class ... I am getting configuration error.

I tried { ? = call package.function(:a, :b, :c) as result from dual } { ? = call package.function(:a, :b, :c) as result from dual } , even this is also not working.

Answer 1

There are some limitations when calling ORACLE functions/procedures with nHibernate.
As stated in the reference documentation (17.2.2.1):

For Oracle the following rules apply :

A function must return a result set. The first parameter of a procedure must be an OUT that returns a result set. This is done by using a SYS_REFCURSOR type in Oracle 9 or 10. In Oracle you need to define a REF CURSOR type, see Oracle literature.

I've tried to play a little bit with it as I am having the same problem.

Here is the PACKAGE-PROCEDURE:

HEAD:

create or replace
PACKAGE           "MYPACKAGE" AS

    TYPE ReferenceCursor IS REF CURSOR;

    PROCEDURE  usp_GetDual 
    (
    pCursor OUT ReferenceCursor,
    a IN CHAR,
    b IN CHAR
    );

END MYPACKAGE;

BODY:

PROCEDURE usp_GetDual
    (
          pCursor OUT ReferenceCursor,
          a IN CHAR,
          b IN CHAR
    )

  IS

    err_code NUMBER;
    err_msg VARCHAR2(200);

  BEGIN

  OPEN pCursor FOR
    SELECT * FROM dual;

   EXCEPTION
    WHEN OTHERS THEN 
        err_code := SQLCODE;
        err_msg := substr(SQLERRM, 1, 200);

END usp_GetDual;

This my mapping file:

<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="MyAssembly">
    <sql-query name="GetDaul">
        { call MYPACKAGE.usp_GetDual ( :a, :b ) }
    </sql-query>
</hibernate-mapping>

and this is the code I've used to test it:

var value = Session.GetNamedQuery("GetDaul")
    .SetParameter<string>("a", "AAA")
    .SetParameter<string>("b", "BBB")
    .UniqueResult();

As you can see the REF CURSOR must be the first parameter in your procedure ( pCursor OUT ReferenceCursor ) and you do not need to reference it in your mapping or your call.

If you want to return entities, things get a little bit more complicated.

Your mapping file must specify the return type (class):

<?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="MyAssembly">
    <sql-query name="GetOrders">
         <return class="MyAssembly.Domain.MyOrder, MyAssembly" />
         { call MYPACKAGE.usp_GetOrders ( :pCompanyCode , :pOrderNumer ) }
    </sql-query>
</hibernate-mapping>

You have to define your entity:

public class MyOrder
{
    public virtual string Number { get; set; }
    public virtual int Ver { get; private set; }
    public virtual string Company { get; set; }
    public virtual string Customer { get; set; }

    public override bool Equals(object obj)
    {
        if (obj == null)
            return false;
        Order order = obj as Order;
        if (order == null)
            return false;
        if (this.Number.Trim() == order.Number.Trim() &&
            this.Ver == order.Ver &&
            this.Company.Trim() == order.Company.Trim()
            )
            return true;
        else
            return false;
    }

    public override int GetHashCode()
    {
        int hash = 0;
        hash = hash +
            (null == this.Number ? 0 : this.Number.GetHashCode())
            +
            (this.Ver.GetHashCode())
            +
            (null == this.Company ? 0 : this.Company.GetHashCode());

        return (hash);
    }
}

and this is the mapping file for your entity:

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="MyAssembly" namespace="MyAssembly.Domain">
  <class name="MyOrder" table="OCSAORH" mutable="false">
    <composite-id>
      <key-property name="Number" column="OCHORDN" type="String" length="10"></key-property>
      <key-property name="Ver" column="OCHAMND" type="Int32"></key-property>
      <key-property name="Company" column="OCHCOSC" type="String" length="5"></key-property>
    </composite-id>
    <property name="Customer" column="OCHCLII" type="String"></property>
  </class>
</hibernate-mapping>

This is my ORACLE package:

PROCEDURE usp_GetOrders 
          (
          pCursor OUT ReferenceCursor,
          pCompanyCode IN CHAR,
          pOrderNumer IN CHAR
      )

  IS

    err_code NUMBER;
    err_msg VARCHAR2(200);

  BEGIN

  OPEN pCursor FOR
       SELECT 
            OCSAORH.*
      FROM OCSAORH 
            WHERE OCSAORH.OCHAMND = 0
                AND OCSAORH.OCHCOSC = pCompanyCode
                AND OCSAORH.OCHORDN = pOrderNumer;              
    EXCEPTION
            WHEN OTHERS THEN 
          err_code := SQLCODE;
          err_msg := substr(SQLERRM, 1, 200);

END usp_GetOrders;

And now you can easily get your orders using parameters:

var listOfOrders = Session.GetNamedQuery("GetOrder")
    .SetParameter<string>("pCompanyCode", "ABC")
        .SetParameter<string>("pOrderNumer", "XYZ")
        .List<Domain.MyOrder>();

This article helped me to understand how thing must be done.

Answer 2

I solve it basing on this post mapping-to-oracle-stored-procedure-with-fluent-nhibernate

Here is my summary:

1. In the procedure you have to declare a first parameter of type OUT SYS_REFCURSOR . ex: p_cursor OUT SYS_REFCURSOR, MyVar1 int, MyVar2 nvarchar

2. To return the resulset do

    OPEN p_cursor FOR <select statement here>; 

   in my case was a dynamic query and it works like a charm.

3. In the hbm mapping surround the call between

    { } 

   ex:

     { call MyProc (MyVar1, MyVar2) } 

   If you do not use the { } , nhibernate throws exception of "incorrect number of arguments".

I hope this helps someone.

Answer 3

With the same thing on my side and on Oracle, NHibernate seems to loose the name of the procedure inside the package. So let's suppose the example upfront: call MYPACKAGE.usp_GetOrders ( :pCompanyCode , :pOrderNumer ) --> result that the package MyPackage is not a stored procedure.

WARN: Oracle.DataAccess.Client.OracleException ORA-06550: line 1, column 7: PLS-00221: 'MYPACKAGE' is not a procedure or is undefined ORA-06550: line 1, column 7:

Answer 4

I got the same trouble. I solved it by this:

Oracle PL/SQL in MyPackage:

...
function MyFunction(a number) return number is
n number;
pragma autonomous_transaction; -- Important!
begin
   n:=apps.fnd_request.submit_request( ... );
   commit; -- Important!
   return n;
end;

mapping.hbm.xml: (Embedded Resource)

  ...
  <sql-query name='MyFunctionQuery'>
    <query-param name='par' type='System.Int64'/>
    <return-scalar column='ret' type='System.Int64'/>
    <![CDATA[ 
      select MyPackage.MyFunction(:par) as ret from dual
    ]]>
  </sql-query>

C#>

 ...
 IQuery Q = session.GetNamedQuery("MyFunctionQuery")
                   .SetParameter("par", 1);
 var result = Q.UniqueResult();

Best regards.