Function transformParamRef

src/backend/parser/parse_expr.c:858–879

}

static Node *
transformParamRef(ParseState *pstate, ParamRef *pref)
{
	Node	   *result;

	/*
	 * The core parser knows nothing about Params.  If a hook is supplied,
	 * call it.  If not, or if the hook returns NULL, throw a generic error.
	 */
	if (pstate->p_paramref_hook != NULL)
		result = pstate->p_paramref_hook(pstate, pref);
	else
		result = NULL;

	if (result == NULL)
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_PARAMETER),
				 errmsg("there is no parameter $%d", pref->number),
				 parser_errposition(pstate, pref->location)));

	return result;
}

/* Test whether an a_expr is a plain NULL constant or not */
static bool