Function PQsendPrepare

src/interfaces/libpq/fe-exec.c:1517–1610

* PQsendPrepare * Submit a Parse message, but don't wait for it to finish * * Returns: 1 if successfully submitted * 0 if error (conn->errorMessage is set) */

 *			0 if error (conn->errorMessage is set)
 */
int
PQsendPrepare(PGconn *conn,
			  const char *stmtName, const char *query,
			  int nParams, const Oid *paramTypes)
{
	PGcmdQueueEntry *entry = NULL;

	if (!PQsendQueryStart(conn, true))
		return 0;

	/* check the arguments */
	if (!stmtName)
	{
		appendPQExpBufferStr(&conn->errorMessage,
							 libpq_gettext("statement name is a null pointer\n"));
		return 0;
	}
	if (!query)
	{
		appendPQExpBufferStr(&conn->errorMessage,
							 libpq_gettext("command string is a null pointer\n"));
		return 0;
	}
	if (nParams < 0 || nParams > PQ_QUERY_PARAM_MAX_LIMIT)
	{
		appendPQExpBuffer(&conn->errorMessage,
						  libpq_gettext("number of parameters must be between 0 and %d\n"),
						  PQ_QUERY_PARAM_MAX_LIMIT);
		return 0;
	}

	entry = pqAllocCmdQueueEntry(conn);
	if (entry == NULL)
		return 0;				/* error msg already set */

	/* construct the Parse message */
	if (pqPutMsgStart('P', conn) < 0 ||
		pqPuts(stmtName, conn) < 0 ||
		pqPuts(query, conn) < 0)
		goto sendFailed;

	if (nParams > 0 && paramTypes)
	{
		int			i;

		if (pqPutInt(nParams, 2, conn) < 0)
			goto sendFailed;
		for (i = 0; i < nParams; i++)
		{
			if (pqPutInt(paramTypes[i], 4, conn) < 0)
				goto sendFailed;
		}
	}
	else
	{
		if (pqPutInt(0, 2, conn) < 0)
			goto sendFailed;
	}