authors.h

不好意思

// Authors.h : Declaration of the CAuthors

#pragma once

// code generated on Wednesday, April 17, 2002, 10:40 AM

class CAuthorsAccessor
{
public:
	LONG m_Au_ID;
	TCHAR m_Author[51];
	SHORT m_YearBorn;

	// The following wizard-generated data members contain status
	// values for the corresponding fields in the column map. You
	// can use these values to hold NULL values that the database
	// returns or to hold error information when the compiler returns
	// errors. See Field Status Data Members in Wizard-Generated
	// Accessors in the Visual C++ documentation for more information
	// on using these fields.
	// NOTE: You must initialize these fields before setting/inserting data!

	DBSTATUS m_dwAu_IDStatus;
	DBSTATUS m_dwAuthorStatus;
	DBSTATUS m_dwYearBornStatus;

	// The following wizard-generated data members contain length
	// values for the corresponding fields in the column map.
	// NOTE: For variable-length columns, you must initialize these
	//       fields before setting/inserting data!

	DBLENGTH m_dwAu_IDLength;
	DBLENGTH m_dwAuthorLength;
	DBLENGTH m_dwYearBornLength;


	void GetRowsetProperties(CDBPropSet* pPropSet)
	{
		pPropSet->AddProperty(DBPROP_CANFETCHBACKWARDS, true, DBPROPOPTIONS_OPTIONAL);
		pPropSet->AddProperty(DBPROP_CANSCROLLBACKWARDS, true, DBPROPOPTIONS_OPTIONAL);
                pPropSet->AddProperty(DBPROP_IRowsetChange, true, DBPROPOPTIONS_OPTIONAL);
                pPropSet->AddProperty(DBPROP_UPDATABILITY, DBPROPVAL_UP_CHANGE | DBPROPVAL_UP_INSERT | DBPROPVAL_UP_DELETE);

	}

	HRESULT OpenDataSource()
	{
		CDataSource _db;
		HRESULT hr;
		hr = _db.OpenFromInitializationString(L"Provider=Microsoft.Jet.OLEDB.4.0;User ID=Admin;Data Source=C:\\vcppnet\\Ex27\\Biblio.mdb;Mode=Share Deny None;Extended Properties=\"\";Jet OLEDB:System database=\"\";Jet OLEDB:Registry Path=\"\";Jet OLEDB:Database Password=\"\";Jet OLEDB:Engine Type=4;Jet OLEDB:Database Locking Mode=0;Jet OLEDB:Global Partial Bulk Ops=2;Jet OLEDB:Global Bulk Transactions=1;Jet OLEDB:New Database Password=\"\";Jet OLEDB:Create System Database=False;Jet OLEDB:Encrypt Database=False;Jet OLEDB:Don't Copy Locale on Compact=False;Jet OLEDB:Compact Without Replica Repair=False;Jet OLEDB:SFP=False");
		if (FAILED(hr))
		{
#ifdef _DEBUG
			AtlTraceErrorRecords(hr);
#endif
			return hr;
		}
		return m_session.Open(_db);
	}

	void CloseDataSource()
	{
		m_session.Close();
	}

	operator const CSession&()
	{
		return m_session;
	}

	CSession m_session;

	DEFINE_COMMAND_EX(CAuthorsAccessor, L" \
	SELECT \
		Au_ID, \
		Author, \
		`Year Born` \
		FROM Authors")


	// In order to fix several issues with some providers, the code below may bind
	// columns in a different order than reported by the provider

	BEGIN_COLUMN_MAP(CAuthorsAccessor)
		COLUMN_ENTRY_LENGTH_STATUS(1, m_Au_ID, m_dwAu_IDLength, m_dwAu_IDStatus)
		COLUMN_ENTRY_LENGTH_STATUS(2, m_Author, m_dwAuthorLength, m_dwAuthorStatus)
		COLUMN_ENTRY_LENGTH_STATUS(3, m_YearBorn, m_dwYearBornLength, m_dwYearBornStatus)
	END_COLUMN_MAP()
};

class CAuthors : public CCommand<CAccessor<CAuthorsAccessor> >
{
public:
	HRESULT OpenAll()
	{
		HRESULT hr;
		hr = OpenDataSource();
		if (FAILED(hr))
			return hr;
		__if_exists(GetRowsetProperties)
		{
			CDBPropSet propset(DBPROPSET_ROWSET);
			__if_exists(HasBookmark)
			{
				propset.AddProperty(DBPROP_IRowsetLocate, true);
			}
			GetRowsetProperties(&propset);
			return OpenRowset(&propset);
		}
		__if_not_exists(GetRowsetProperties)
		{
			__if_exists(HasBookmark)
			{
				CDBPropSet propset(DBPROPSET_ROWSET);
				propset.AddProperty(DBPROP_IRowsetLocate, true);
				return OpenRowset(&propset);
			}
		}
		return OpenRowset();
	}

	HRESULT OpenRowset(DBPROPSET *pPropSet = NULL)
	{
		HRESULT hr = Open(m_session, NULL, pPropSet);
#ifdef _DEBUG
		if(FAILED(hr))
			AtlTraceErrorRecords(hr);
#endif
		return hr;
	}

	void CloseAll()
	{
		Close();
		ReleaseCommand();
		CloseDataSource();
	}
};