コード例 #1
1
ファイル: common.c プロジェクト: sunyangkobe/cscd43
/*
 * SendQuery: send the query string to the backend
 * (and print out results)
 *
 * Note: This is the "front door" way to send a query. That is, use it to
 * send queries actually entered by the user. These queries will be subject to
 * single step mode.
 * To send "back door" queries (generated by slash commands, etc.) in a
 * controlled way, use PSQLexec().
 *
 * Returns true if the query executed successfully, false otherwise.
 */
bool
SendQuery(const char *query)
{
	PGresult   *results;
	TimevalStruct before,
				after;
	bool		OK;

	if (!pset.db)
	{
		psql_error("You are currently not connected to a database.\n");
		return false;
	}

	if (GetVariableBool(pset.vars, "SINGLESTEP"))
	{
		char		buf[3];

		printf(gettext("***(Single step mode: verify command)*******************************************\n"
					   "%s\n"
					   "***(press return to proceed or enter x and return to cancel)********************\n"),
			   query);
		fflush(stdout);
		if (fgets(buf, sizeof(buf), stdin) != NULL)
			if (buf[0] == 'x')
				return false;
	}
	else if (VariableEquals(pset.vars, "ECHO", "queries"))
	{
		puts(query);
		fflush(stdout);
	}

	SetCancelConn();

	if (PQtransactionStatus(pset.db) == PQTRANS_IDLE &&
		!GetVariableBool(pset.vars, "AUTOCOMMIT") &&
		!is_transact_command(query))
	{
		results = PQexec(pset.db, "BEGIN");
		if (PQresultStatus(results) != PGRES_COMMAND_OK)
		{
			psql_error("%s", PQerrorMessage(pset.db));
			PQclear(results);
			ResetCancelConn();
			return false;
		}
		PQclear(results);
	}

	if (pset.timing)
		GETTIMEOFDAY(&before);

	results = PQexec(pset.db, query);

	/* these operations are included in the timing result: */
	OK = (AcceptResult(results) && ProcessCopyResult(results));

	if (pset.timing)
		GETTIMEOFDAY(&after);

	/* but printing results isn't: */
	if (OK)
		OK = PrintQueryResults(results);

	PQclear(results);

	/* Possible microtiming output */
	if (OK && pset.timing)
		printf(gettext("Time: %.3f ms\n"), DIFF_MSEC(&after, &before));

	/* check for events that may occur during query execution */

	if (pset.encoding != PQclientEncoding(pset.db) &&
		PQclientEncoding(pset.db) >= 0)
	{
		/* track effects of SET CLIENT_ENCODING */
		pset.encoding = PQclientEncoding(pset.db);
		pset.popt.topt.encoding = pset.encoding;
		SetVariable(pset.vars, "ENCODING",
					pg_encoding_to_char(pset.encoding));
	}

	PrintNotifications();

	return OK;
}
コード例 #2
0
ファイル: common.c プロジェクト: AllenDou/postgresql
/*
 * SendQuery: send the query string to the backend
 * (and print out results)
 *
 * Note: This is the "front door" way to send a query. That is, use it to
 * send queries actually entered by the user. These queries will be subject to
 * single step mode.
 * To send "back door" queries (generated by slash commands, etc.) in a
 * controlled way, use PSQLexec().
 *
 * Returns true if the query executed successfully, false otherwise.
 */
bool
SendQuery(const char *query)
{
	PGresult   *results;
	PGTransactionStatusType transaction_status;
	double		elapsed_msec = 0;
	bool		OK,
				on_error_rollback_savepoint = false;
	static bool on_error_rollback_warning = false;

	if (!pset.db)
	{
		psql_error("You are currently not connected to a database.\n");
		return false;
	}

	if (pset.singlestep)
	{
		char		buf[3];

		printf(_("***(Single step mode: verify command)*******************************************\n"
				 "%s\n"
				 "***(press return to proceed or enter x and return to cancel)********************\n"),
			   query);
		fflush(stdout);
		if (fgets(buf, sizeof(buf), stdin) != NULL)
			if (buf[0] == 'x')
				return false;
	}
	else if (pset.echo == PSQL_ECHO_QUERIES)
	{
		puts(query);
		fflush(stdout);
	}

	if (pset.logfile)
	{
		fprintf(pset.logfile,
				_("********* QUERY **********\n"
				  "%s\n"
				  "**************************\n\n"), query);
		fflush(pset.logfile);
	}

	SetCancelConn();

	transaction_status = PQtransactionStatus(pset.db);

	if (transaction_status == PQTRANS_IDLE &&
		!pset.autocommit &&
		!command_no_begin(query))
	{
		results = PQexec(pset.db, "BEGIN");
		if (PQresultStatus(results) != PGRES_COMMAND_OK)
		{
			psql_error("%s", PQerrorMessage(pset.db));
			PQclear(results);
			ResetCancelConn();
			return false;
		}
		PQclear(results);
		transaction_status = PQtransactionStatus(pset.db);
	}

	if (transaction_status == PQTRANS_INTRANS &&
		pset.on_error_rollback != PSQL_ERROR_ROLLBACK_OFF &&
		(pset.cur_cmd_interactive ||
		 pset.on_error_rollback == PSQL_ERROR_ROLLBACK_ON))
	{
		if (on_error_rollback_warning == false && pset.sversion < 80000)
		{
			fprintf(stderr, _("The server (version %d.%d) does not support savepoints for ON_ERROR_ROLLBACK.\n"),
					pset.sversion / 10000, (pset.sversion / 100) % 100);
			on_error_rollback_warning = true;
		}
		else
		{
			results = PQexec(pset.db, "SAVEPOINT pg_psql_temporary_savepoint");
			if (PQresultStatus(results) != PGRES_COMMAND_OK)
			{
				psql_error("%s", PQerrorMessage(pset.db));
				PQclear(results);
				ResetCancelConn();
				return false;
			}
			PQclear(results);
			on_error_rollback_savepoint = true;
		}
	}

	if (pset.fetch_count <= 0 || !is_select_command(query))
	{
		/* Default fetch-it-all-and-print mode */
		instr_time	before,
					after;

		if (pset.timing)
			INSTR_TIME_SET_CURRENT(before);

		results = PQexec(pset.db, query);

		/* these operations are included in the timing result: */
		ResetCancelConn();
		OK = ProcessResult(&results);

		if (pset.timing)
		{
			INSTR_TIME_SET_CURRENT(after);
			INSTR_TIME_SUBTRACT(after, before);
			elapsed_msec = INSTR_TIME_GET_MILLISEC(after);
		}

		/* but printing results isn't: */
		if (OK && results)
			OK = PrintQueryResults(results);
	}
	else
	{
		/* Fetch-in-segments mode */
		OK = ExecQueryUsingCursor(query, &elapsed_msec);
		ResetCancelConn();
		results = NULL;			/* PQclear(NULL) does nothing */
	}

	/* If we made a temporary savepoint, possibly release/rollback */
	if (on_error_rollback_savepoint)
	{
		const char *svptcmd = NULL;

		transaction_status = PQtransactionStatus(pset.db);

		switch (transaction_status)
		{
			case PQTRANS_INERROR:
				/* We always rollback on an error */
				svptcmd = "ROLLBACK TO pg_psql_temporary_savepoint";
				break;

			case PQTRANS_IDLE:
				/* If they are no longer in a transaction, then do nothing */
				break;

			case PQTRANS_INTRANS:

				/*
				 * Do nothing if they are messing with savepoints themselves:
				 * If the user did RELEASE or ROLLBACK, our savepoint is gone.
				 * If they issued a SAVEPOINT, releasing ours would remove
				 * theirs.
				 */
				if (results &&
					(strcmp(PQcmdStatus(results), "SAVEPOINT") == 0 ||
					 strcmp(PQcmdStatus(results), "RELEASE") == 0 ||
					 strcmp(PQcmdStatus(results), "ROLLBACK") == 0))
					svptcmd = NULL;
				else
					svptcmd = "RELEASE pg_psql_temporary_savepoint";
				break;

			case PQTRANS_ACTIVE:
			case PQTRANS_UNKNOWN:
			default:
				OK = false;
				/* PQTRANS_UNKNOWN is expected given a broken connection. */
				if (transaction_status != PQTRANS_UNKNOWN || ConnectionUp())
					psql_error("unexpected transaction status (%d)\n",
							   transaction_status);
				break;
		}

		if (svptcmd)
		{
			PGresult   *svptres;

			svptres = PQexec(pset.db, svptcmd);
			if (PQresultStatus(svptres) != PGRES_COMMAND_OK)
			{
				psql_error("%s", PQerrorMessage(pset.db));
				PQclear(svptres);

				PQclear(results);
				ResetCancelConn();
				return false;
			}
			PQclear(svptres);
		}
	}

	PQclear(results);

	/* Possible microtiming output */
	if (pset.timing)
		printf(_("Time: %.3f ms\n"), elapsed_msec);

	/* check for events that may occur during query execution */

	if (pset.encoding != PQclientEncoding(pset.db) &&
		PQclientEncoding(pset.db) >= 0)
	{
		/* track effects of SET CLIENT_ENCODING */
		pset.encoding = PQclientEncoding(pset.db);
		pset.popt.topt.encoding = pset.encoding;
		SetVariable(pset.vars, "ENCODING",
					pg_encoding_to_char(pset.encoding));
	}

	PrintNotifications();

	return OK;
}