Passing an argument to an Oracle Stored Procedure

Question

This may have been asked before, so I'm sorry if this is repeated. If you can link to where I can find an answer, I would really appreciate it. I've looked around at other answers and on Google but nothing seems to have worked yet. So...

I have a stored procedure in Oracle 11g (that I cannot change) and I have to use OCI (no choice here).

The stored procedure declaration is like:

PROCEDURE GetEmployee(EID IN NUMBER, rcursor IN OUT cursor_type);

How do I call this in C?

I tried to use the OCI example here as a basis, modifying it so:

char * query =  "DECLARE \
     EID NUMBER; \
     RCURSOR CORP.EMPASSIST.cursor_type; \
     BEGIN \
       EID:= NULL; \
       RCURSOR := NULL; \
       EMPASSIST.GetEmployee( EID=> EID, RCURSOR => RCURSOR ); \
       :RCURSOR := RCURSOR; --<-- Cursor \
     END;";

OCIError * db_error;
OCIStmt * statement;
OCIEnv * environment;
OCIServer * server;
OCISession * session;
OCISvcCtx * service;

OCIBind * cursor_bind;
OCIBind * eid_bind;
OCIStmt * cursor_stm;
OCIStmt * eid_stm;

retval += OCIStmtPrepare(statement, db_error, (OraText *) query, strlen(query), OCI_NTV_SYNTAX, OCI_DEFAULT);
retval += OCIHandleAlloc(environment, (void **) &eid_stm, OCI_HTYPE_STMT, 0, NULL);
retval += OCIHandleAlloc(environment, (void **) &cursor_stm, OCI_HTYPE_STMT, 0, NULL);
retval += OCIBindByPos(statement, &eid_bind, db_error, 1, &eid_stm, 0, SQLT_NUM, NULL, 0, NULL, 0, 0, OCI_DEFAULT);
retval += OCIBindByPos(statement, &cursor_bind, db_error, 2, &cursor_stm, 0, SQLT_RSET, NULL, 0, NULL, 0, 0, OCI_DEFAULT);

retval += OCIStmtExecute(service, statement, db_error, 1, 0, NULL, NULL, OCI_COMMIT_ON_SUCCESS);

but this does not seem to work for me. All the handle allocation seems to work just fine. No errors.

However, it fails on the OCIStmtExecute step. I have to BindByPos after that, and they fail too, but I'm guessing that is because of the statement execution failure.

Please help!

==========================================================================

Fixed: Posting in answers in case it helps someone else

Answer 1

It would help if you post the actual error.

However as with named data types, binding REFs is a two-step process. First, call OCIBindByName() or OCIBindByPos(), and then call OCIBindObject().

REFs are bound using the SQLT_REF datatype. When SQLT_REF is used, then the program variable being bound must be of type OCIRef *.

With inheritance and REF substitutability, you can bind a REF value to a subtype instance where a REF to the supertype is expected.

Answer 2

Changed:

char * query =  "DECLARE \ 
 EID NUMBER; \ 
 RCURSOR CORP.EMPASSIST.cursor_type; \ 
 BEGIN \ 
   EID:= NULL; \ 
   RCURSOR := NULL; \ 
   EMPASSIST.GetEmployee( EID=> EID, RCURSOR => RCURSOR ); \ 
   :RCURSOR := RCURSOR; --<-- Cursor \ 
 END;"; 

to

int eid = /* whatever value */;
char * query_template = "CALL EMPASSIST.GetEmployee(%d, :RCURSOR)";
char query[1023] =  {'\0'};
snprintf(query, sizeof(query) - 1, query_template, eid);

Changed the rest to:

OCIError * db_error;   
OCIStmt * statement;   
OCIEnv * environment;   
OCISvcCtx * service;   

OCIBind * cursor_bind;   
OCIStmt * cursor_stm;   

retval += OCIHandleAlloc(environment, (void **) &statement, OCI_HTYPE_STMT, 0, NULL);
retval += OCIStmtPrepare(statement, db_error, (OraText *) query, strlen(query), OCI_NTV_SYNTAX, OCI_DEFAULT);   
retval += OCIHandleAlloc(environment, (void **) &cursor_stm, OCI_HTYPE_STMT, 0, NULL);   
retval += OCIBindByName(statement, &cursorbind, db_error, (OraText *) ":RCURSOR", strlen(":RCURSOR"), &cursor, 0, SQLT_RSET, 0, 0, 0, 0, 0, OCI_DEFAULT);   

retval += OCIStmtExecute(service, statement, db_error, 1, 0, NULL, NULL, OCI_COMMIT_ON_SUCCESS);