C++ IBS类代码示例

bool StatementImpl::Fetch(IBPP::Row& row)
{
	if (! mResultSetAvailable)
		throw LogicExceptionImpl("Statement::Fetch(row)",
			_("No statement has been executed or no result set available."));

	RowImpl* rowimpl = new RowImpl(*mOutRow);
	row = rowimpl;

	IBS status;
	int code = (*gds.Call()->m_dsql_fetch)(status.Self(), &mHandle, 1,
					rowimpl->Self());
	if (code == 100)	// This special code means "no more rows"
	{
		mResultSetAvailable = false;
		// Oddly enough, fetching rows up to the last one seems to open
		// an 'implicit' cursor that needs to be closed.
		mCursorOpened = true;
		CursorFree();	// Free the explicit or implicit cursor/result-set
		row.clear();
		return false;
	}
	if (status.Errors())
	{
		Close();
		row.clear();
		throw SQLExceptionImpl(status, "Statement::Fetch(row)",
			_("isc_dsql_fetch failed."));
	}

	return true;
}

void EventsImpl::Cancel()
{
	if (mQueued)
	{
		if (mDatabase->GetHandle() == 0) throw LogicExceptionImpl("EventsImpl::Cancel",
			_("Database is not connected"));

		IBS vector;

		// A call to cancel_events will call *once* the handler routine, even
		// though no events had fired. This is why we first set mEventsQueued
		// to false, so that we can be sure to dismiss those unwanted callbacks
		// subsequent to the execution of isc_cancel_events().
		mTrapped = false;
		mQueued = false;
		(*gds.Call()->m_cancel_events)(vector.Self(), mDatabase->GetHandlePtr(), &mId);

	    if (vector.Errors())
		{
			mQueued = true;	// Need to restore this as cancel failed
	    	throw SQLExceptionImpl(vector, "EventsImpl::Cancel",
	    		_("isc_cancel_events failed"));
		}

		mId = 0;	// Should be, but better be safe
	}
}

void ServiceImpl::ModifyUser(const IBPP::User& user)
{
	if (mHandle == 0)
		throw LogicExceptionImpl("Service::ModifyUser", _("Service is not connected."));
	if (user.username.empty())
		throw LogicExceptionImpl("Service::ModifyUser", _("Username required."));

	IBS status;
	SPB spb;

	spb.Insert(isc_action_svc_modify_user);
	spb.InsertString(isc_spb_sec_username, 2, user.username.c_str());
	if (! user.password.empty())
			spb.InsertString(isc_spb_sec_password, 2, user.password.c_str());
	if (! user.firstname.empty())
			spb.InsertString(isc_spb_sec_firstname, 2, user.firstname.c_str());
	if (! user.middlename.empty())
			spb.InsertString(isc_spb_sec_middlename, 2, user.middlename.c_str());
	if (! user.lastname.empty())
			spb.InsertString(isc_spb_sec_lastname, 2, user.lastname.c_str());
	if (user.userid != 0)
			spb.InsertQuad(isc_spb_sec_userid, (int32_t)user.userid);
	if (user.groupid != 0)
			spb.InsertQuad(isc_spb_sec_groupid, (int32_t)user.groupid);

	(*gds.Call()->m_service_start)(status.Self(), &mHandle, 0, spb.Size(), spb.Self());
	if (status.Errors())
		throw SQLExceptionImpl(status, "Service::ModifyUser", _("isc_service_start failed"));

	Wait();
}

void DatabaseImpl::Create(int dialect)
{
	if (mHandle != 0)
		throw LogicExceptionImpl("Database::Create", _("Database is already connected."));
	if (mDatabaseName.empty())
		throw LogicExceptionImpl("Database::Create", _("Unspecified database name."));
	if (mUserName.empty())
		throw LogicExceptionImpl("Database::Create", _("Unspecified user name."));
	if (dialect != 1 && dialect != 3)
		throw LogicExceptionImpl("Database::Create", _("Only dialects 1 and 3 are supported."));

	// Build the SQL Create Statement
	std::string create;
	create.assign("CREATE DATABASE '");
	if (! mServerName.empty()) create.append(mServerName).append(":");
	create.append(mDatabaseName).append("' ");

	create.append("USER '").append(mUserName).append("' ");
	if (! mUserPassword.empty())
		create.append("PASSWORD '").append(mUserPassword).append("' ");

	if (! mCreateParams.empty()) create.append(mCreateParams);

	// Call ExecuteImmediate to create the database
	isc_tr_handle tr_handle = 0;
	IBS status;
    (*gds.Call()->m_dsql_execute_immediate)(status.Self(), &mHandle, &tr_handle,
    	0, const_cast<char*>(create.c_str()), short(dialect), NULL);
    if (status.Errors())
		throw SQLExceptionImpl(status, "Database::Create", _("isc_dsql_execute_immediate failed"));

	Disconnect();
}

bool StatementImpl::Fetch()
{
	if (! mResultSetAvailable)
		throw LogicExceptionImpl("Statement::Fetch",
			_("No statement has been executed or no result set available."));

	IBS status;
	ISC_STATUS code = (*gds.Call()->m_dsql_fetch)(status.Self(), &mHandle, 1, mOutRow->Self());
	if (code == 100)	// This special code means "no more rows"
	{
		mResultSetAvailable = false;
		// Oddly enough, fetching rows up to the last one seems to open
		// an 'implicit' cursor that needs to be closed.
		mCursorOpened = true;
		CursorFree();	// Free the explicit or implicit cursor/result-set
		return false;
	}
	if (status.Errors())
	{
		Close();
		throw SQLExceptionImpl(status, "Statement::Fetch",
			_("isc_dsql_fetch failed."));
	}

    // Close the 'implicit' cursor to allow for forther Execute() calls
    // on the prepared statement without fetching up to the last row
	mCursorOpened = true;
	return true;
}

void ServiceImpl::Wait()
{
	IBS status;
	SPB spb;
	RB result(1024);
	std::string msg;

	spb.Insert(isc_info_svc_line);
	for (;;)
	{
		// Sleeps 1 millisecond upfront. This will release the remaining
		// timeslot of the thread. Doing so will give a good chance for small
		// services tasks to finish before we check if they are still running.
		// The deal is to limit (in that particular case) the number of loops
		// polling _service_query that will happen.

		Sleep(1);

		// _service_query will only block until a line of result is available
		// (or until the end of the task if it does not report information) 
		(*gds.Call()->m_service_query)(status.Self(), &mHandle, 0, 0,	0,
			spb.Size(),	spb.Self(),	result.Size(), result.Self());
		if (status.Errors())
			throw SQLExceptionImpl(status, "ServiceImpl::Wait", _("isc_service_query failed"));

		// If message length is	zero bytes,	task is	finished
		if (result.GetString(isc_info_svc_line,	msg) ==	0) return;

		status.Reset();
		result.Reset();
	}
}

void TransactionImpl::RollbackRetain()
{
	if (mHandle == 0)
		throw LogicExceptionImpl("Transaction::RollbackRetain", _("Transaction is not started."));

	IBS status;

	(*gds.Call()->m_rollback_retaining)(status.Self(), &mHandle);
	if (status.Errors())
		throw SQLExceptionImpl(status, "Transaction::RollbackRetain");
}

void TransactionImpl::Rollback()
{
	if (mHandle == 0) return;	// Transaction not started anyway

	IBS status;

	(*gds.Call()->m_rollback_transaction)(status.Self(), &mHandle);
	if (status.Errors())
		throw SQLExceptionImpl(status, "Transaction::Rollback");
	mHandle = 0;	// Should be, better be sure
}

void StatementImpl::CursorFree()
{
	if (mCursorOpened)
	{
		mCursorOpened = false;
		if (mHandle != 0)
		{
			IBS status;
			(*gds.Call()->m_dsql_free_statement)(status.Self(), &mHandle, DSQL_close);
			if (status.Errors())
				throw SQLExceptionImpl(status, "StatementImpl::CursorFree(DSQL_close)",
					_("isc_dsql_free_statement failed."));
		}
	}
}

void ServiceImpl::Disconnect()
{
	if (mHandle	== 0) return; // Already disconnected
	
	IBS status;

	// Detach from the service manager
	(*gds.Call()->m_service_detach)(status.Self(), &mHandle);

	// Set mHandle to 0 now, just in case we need to throw, because Disconnect()
	// is called from Service destructor and we want to maintain a coherent state.
	mHandle	= 0;
	if (status.Errors())
		throw SQLExceptionImpl(status, "Service::Disconnect", _("isc_service_detach failed"));
}

void TransactionImpl::Rollback()
{
    if (mHandle == 0) return;   // Transaction not started anyway

    IBS status;

    (*gds.Call()->m_rollback_transaction)(status.Self(), &mHandle);
    if (status.Errors())
        throw SQLExceptionImpl(status, "Transaction::Rollback");
    mHandle = 0;    // Should be, better be sure

    /*
    size_t i;
    for (i = mStatements.size(); i != 0; i--)
        mStatements[i-1]->CursorFree();
    */
}

void DatabaseImpl::Disconnect()
{
	if (mHandle == 0) return;	// Not connected anyway

	// Put the connection to rest
	Inactivate();

	// Detach from the server
	IBS status;
    (*gds.Call()->m_detach_database)(status.Self(), &mHandle);

    // Should we throw, set mHandle to 0 first, because Disconnect() may
	// be called from Database destructor (keeps the object coherent).
	mHandle = 0;
    if (status.Errors())
		throw SQLExceptionImpl(status, "Database::Disconnect", _("isc_detach_database failed"));
}

void TransactionImpl::Commit()
{
    if (mHandle == 0)
        throw LogicExceptionImpl("Transaction::Commit", _("Transaction is not started."));

    IBS status;

    (*gds.Call()->m_commit_transaction)(status.Self(), &mHandle);
    if (status.Errors())
        throw SQLExceptionImpl(status, "Transaction::Commit");
    mHandle = 0;    // Should be, better be sure

    /*
    size_t i;
    for (i = mStatements.size(); i != 0; i--)
        mStatements[i-1]->CursorFree();
    */
}

const char* ServiceImpl::WaitMsg()
{
	IBS status;
	SPB req;
	RB result(1024);

	req.Insert(isc_info_svc_line);	// Request one line of textual output

	// _service_query will only block until a line of result is available
	// (or until the end of the task if it does not report information)
	(*gds.Call()->m_service_query)(status.Self(), &mHandle, 0, 0, 0,
		req.Size(),	req.Self(),	result.Size(), result.Self());
	if (status.Errors())
		throw SQLExceptionImpl(status, "ServiceImpl::Wait", _("isc_service_query failed"));

	// If message length is	zero bytes,	task is	finished
	if (result.GetString(isc_info_svc_line,	mWaitMessage) == 0) return 0;

	// Task	is not finished, but we	have something to report
	return mWaitMessage.c_str();
}