从SOCI用匿名PL SQL块调用PLsql脚本

Question

I'm searching for a way to call an anonymous PLsql block through SOCI. The data transfer takes place through a refcursor that was previously created as a variable in the script:

variable rc refcursor
declare
   v_obj_id number(4,0) := 1;
   v_obj_def varchar(30);
   v_obj_type number := 1;
begin
  open :rc for
     select v_obj_id, OBJ_DEF_ID
     from MY_OBJECT_DEFS
     where OBJECT_TYPE = v_obj_type;
end;

I need to read the refcursor from my application to retrieve the data. I tried to execute the above through a soci::statement but it gives me the error: ORA-24333: zero iteration count . The PLsql script works fine when executed in SqlPlus.

1. How can I make the connection between the statement and the refcursor rc? Should I use some other SOCI construct (other than statement) for this purpose?
2. I understand there are two instructions in the above script; (i. the refcursor creation, ii. the anonymous PLsql block itself). I'm not sure whether its possible to call multiple instructions in a single SOCI statement. Can this be confirmed?

Following is the what I tried. The sSQL contains the above PLsql script:

dbConn.open("...");
int iObjId;
std::string iObjDefId;
soci::indicator ind_iObjId = soci::i_ok,
        ind_iObjDefId = soci::i_ok;

soci::statement stmt(dbConn);
stmt.alloc();
stmt.prepare(sSQL);
stmt.exchange(soci::into(iObjId, ind_iObjId));
stmt.exchange(soci::into(iObjDefId, ind_iObjDefId));
stmt.define_and_bind();
stmt.execute(false);

while (stmt.fetch())
{
    if (soci::i_ok == ind_iObjId)
        std::cout << "Obj ID: " << iObjId << std::endl;

    if (soci::i_ok == ind_iObjDefId)
        std::cout << "Obj Def ID: " << iObjDefId << std::endl;
}

EDIT: I'm using Oracle 11g

Answer 1

The statement variable rc refcursor is neither SQL nor PL/SQL but part of Oracle's SQL*Plus command-line utility and compatible third party products. I don't know C++ but presumably you would need to define a ref cursor object in the host program.

If this is not feasible, and you are on Oracle 12.1 or later, it's possible that you could use an implicit result set construction, along the lines of

declare
    rc sys_refcursor;
begin
    open rc for select * from dual;
    dbms_sql.return_result(rc);
end;

as discussed in Is it possible to output a SELECT state from a PL/SQL block?