ORA-01008: not all variables bound (in C w OCI)

Question

I have the following C code which uses a stored procedure to insert 2 strings into the database:

char query[1024];

memset(query, 0, sizeof(query));
sprintf(query, "BEGIN bns_saa_message_insert (:1, :2); END;");


/* prepare statement */
if( checkerr(errhp, OCIStmtPrepare(stmthp, errhp, (text *) query,
        (ub4) strlen((char *) query),
        (ub4) OCI_NTV_SYNTAX, (ub4) OCI_DEFAULT)) == OCI_ERROR)
    return -1;


/* bind input params */
if( checkerr(errhp, OCIBindByPos(stmthp, &bndhp, errhp, (ub4) 1, (dvoid *) hostNumber,
        (sword) sizeof(hostNumber) - 1, SQLT_CHR, (dvoid *) 0,
        (ub2 *) 0, (ub2) 0, (ub4) 0, (ub4 *) 0, OCI_DEFAULT)) == OCI_ERROR)
    return -1;

if( checkerr(errhp, OCIBindByPos(stmthp, &bndhp, errhp, (ub4) 1, (dvoid *) saaMessage,
        (sword) sizeof(saaMessage) - 1, SQLT_CHR, (dvoid *) 0,
        (ub2 *) 0, (ub2) 0, (ub4) 0, (ub4 *) 0, OCI_DEFAULT)) == OCI_ERROR)
    return -1;
//end of param binding

printf("query: %s",query);//this shows param1 and param2 have not been replaced when I did the binding above

/* execute the statement */
status = OCIStmtExecute(svchp, stmthp, errhp, (ub4) 1, (ub4) 0,
        (CONST OCISnapshot *) NULL, (OCISnapshot *) NULL, OCI_DEFAULT);

The error I get is :

ORA-01008: not all variables bound

and the printf outlined in the code above outputs:

query: BEGIN bns_saa_message_insert (:1, :2); END;

Question
How do I fix this error?

EDIT
I have seen similar questions answered here in C# or Java, but not C
"ORA-01008: not all variables bound" error
ORA-01008: not all variables bound. They are bound

Answer 1

It looks like a minor mistake. Your second call to OCIBindByPos should use 2 instead of 1 for the fourth parameter:

if( checkerr(errhp, OCIBindByPos(stmthp, &bndhp, errhp, (ub4) 2, (dvoid *) saaMessage,