txtprovidersess.h

本书分为五个部分

// TxtProviderSess.h : CTxtProviderSession 的声明

#pragma once

#include "resource.h"       // 主符号
#include "TxtProviderRS.h"

class CTxtProviderSessionTRSchemaRowset;
class CTxtProviderSessionColSchemaRowset;
class CTxtProviderSessionPTSchemaRowset;


// CTxtProviderSession
class ATL_NO_VTABLE CTxtProviderSession : 
	public CComObjectRootEx<CComSingleThreadModel>,
	public IGetDataSourceImpl<CTxtProviderSession>,
	public IOpenRowsetImpl<CTxtProviderSession>,
	public ISessionPropertiesImpl<CTxtProviderSession>,
	public IObjectWithSiteSessionImpl<CTxtProviderSession>,
	public IDBSchemaRowsetImpl<CTxtProviderSession>,
	public IDBCreateCommandImpl<CTxtProviderSession, CTxtProviderCommand>
{
public:
	CTxtProviderSession()
	{
	}

	DECLARE_PROTECT_FINAL_CONSTRUCT()

	HRESULT FinalConstruct()
	{
		return FInit();
	}
	
	void FinalRelease() 
	{
	}

	STDMETHOD(OpenRowset)(IUnknown *pUnk, DBID *pTID, DBID *pInID, REFIID riid,
					   ULONG cSets, DBPROPSET rgSets[], IUnknown **ppRowset)
	{
		CTxtProviderRowset* pRowset;
		return CreateRowset(pUnk, pTID, pInID, riid, cSets, rgSets, ppRowset, pRowset);
	}

	void SetRestrictions(ULONG cRestrictions, GUID* rguidSchema, ULONG* rgRestrictions)
	{
		for (ULONG l=0; l<cRestrictions; l++)
		{
			// 我们支持对表名称（但仅限于表名称）的限制
			if (InlineIsEqualGUID(rguidSchema[l], DBSCHEMA_TABLES))
				rgRestrictions[l] = 0x04;
			else if (InlineIsEqualGUID(rguidSchema[l], DBSCHEMA_COLUMNS))
				rgRestrictions[l] = 0x04;
			else if (InlineIsEqualGUID(rguidSchema[l], DBSCHEMA_PROVIDER_TYPES))
				rgRestrictions[l] = 0x00;
		}
	}

BEGIN_PROPSET_MAP(CTxtProviderSession)
	BEGIN_PROPERTY_SET(DBPROPSET_SESSION)
		PROPERTY_INFO_ENTRY(SESS_AUTOCOMMITISOLEVELS)
	END_PROPERTY_SET(DBPROPSET_SESSION)
END_PROPSET_MAP()

BEGIN_COM_MAP(CTxtProviderSession)
	COM_INTERFACE_ENTRY(IGetDataSource)
	COM_INTERFACE_ENTRY(IOpenRowset)
	COM_INTERFACE_ENTRY(ISessionProperties)
	COM_INTERFACE_ENTRY(IObjectWithSite)
	COM_INTERFACE_ENTRY(IDBCreateCommand)
	COM_INTERFACE_ENTRY(IDBSchemaRowset)
END_COM_MAP()

BEGIN_SCHEMA_MAP(CTxtProviderSession)
	SCHEMA_ENTRY(DBSCHEMA_TABLES, CTxtProviderSessionTRSchemaRowset)
	SCHEMA_ENTRY(DBSCHEMA_COLUMNS, CTxtProviderSessionColSchemaRowset)
	SCHEMA_ENTRY(DBSCHEMA_PROVIDER_TYPES, CTxtProviderSessionPTSchemaRowset)
END_SCHEMA_MAP()

};

class CTxtProviderSessionTRSchemaRowset : 
	public CSchemaRowsetImpl< CTxtProviderSessionTRSchemaRowset, CTABLESRow, CTxtProviderSession>
{
public:
BEGIN_PROPSET_MAP(CTxtProviderSessionTRSchemaRowset)
	BEGIN_PROPERTY_SET(DBPROPSET_ROWSET)
		PROPERTY_INFO_ENTRY(IAccessor)
		PROPERTY_INFO_ENTRY(IColumnsInfo)
		PROPERTY_INFO_ENTRY(IConvertType)
		PROPERTY_INFO_ENTRY(IRowset)
		PROPERTY_INFO_ENTRY(IRowsetIdentity)
		PROPERTY_INFO_ENTRY(IRowsetInfo)
		PROPERTY_INFO_ENTRY(CANFETCHBACKWARDS)
		PROPERTY_INFO_ENTRY(CANHOLDROWS)
		PROPERTY_INFO_ENTRY(CANSCROLLBACKWARDS)
		PROPERTY_INFO_ENTRY_VALUE(MAXOPENROWS, 0)
		PROPERTY_INFO_ENTRY_VALUE(MAXROWS, 0)
	END_PROPERTY_SET(DBPROPSET_ROWSET)
END_PROPSET_MAP()

	HRESULT Execute(LONG* pcRowsAffected, ULONG, const VARIANT*)
	{
		USES_CONVERSION;
		CTxtProviderWindowsFile wf;
		CTABLESRow trData;
		lstrcpyW(trData.m_szType, OLESTR("TABLE"));
		lstrcpyW(trData.m_szDesc, OLESTR("目录表"));

		HANDLE hFile = INVALID_HANDLE_VALUE;
		TCHAR szDir[MAX_PATH + 1];
		DWORD cbCurDir = GetCurrentDirectory(MAX_PATH, szDir);
		lstrcat(szDir, _T("\\*.*"));
		hFile = FindFirstFile(szDir, &wf);
		if (hFile == INVALID_HANDLE_VALUE)
			return E_FAIL; // 用户没有 c:\ 驱动器
		FindClose(hFile);
		lstrcpynW(trData.m_szTable, T2OLE(szDir), SIZEOF_MEMBER(CTABLESRow, m_szTable));
		if (!m_rgRowData.Add(trData))
			return E_OUTOFMEMORY;
		*pcRowsAffected = 1;
		return S_OK;
	}

	DBSTATUS GetDBStatus(CSimpleRow*, ATLCOLUMNINFO* pInfo)
	{
		if (pInfo->iOrdinal == 1 || pInfo->iOrdinal == 2)
			return DBSTATUS_S_ISNULL;
		return DBSTATUS_S_OK;
	}
};


class CTxtProviderSessionColSchemaRowset : 
	public CSchemaRowsetImpl< CTxtProviderSessionColSchemaRowset, CCOLUMNSRow, CTxtProviderSession>
{
public:
BEGIN_PROPSET_MAP(CTxtProviderSessionColSchemaRowset)
	BEGIN_PROPERTY_SET(DBPROPSET_ROWSET)
		PROPERTY_INFO_ENTRY(IAccessor)
		PROPERTY_INFO_ENTRY(IColumnsInfo)
		PROPERTY_INFO_ENTRY(IConvertType)
		PROPERTY_INFO_ENTRY(IRowset)
		PROPERTY_INFO_ENTRY(IRowsetIdentity)
		PROPERTY_INFO_ENTRY(IRowsetInfo)
		PROPERTY_INFO_ENTRY(CANFETCHBACKWARDS)
		PROPERTY_INFO_ENTRY(CANHOLDROWS)
		PROPERTY_INFO_ENTRY(CANSCROLLBACKWARDS)
		PROPERTY_INFO_ENTRY_VALUE(MAXOPENROWS, 0)
		PROPERTY_INFO_ENTRY_VALUE(MAXROWS, 0)
	END_PROPERTY_SET(DBPROPSET_ROWSET)
END_PROPSET_MAP()

	HRESULT Execute(LONG* pcRowsAffected, ULONG, const VARIANT*)
	{
		USES_CONVERSION;
		CTxtProviderWindowsFile wf;
		HANDLE hFile = INVALID_HANDLE_VALUE;
		TCHAR szDir[MAX_PATH + 1];
		DWORD cbCurDir = GetCurrentDirectory(MAX_PATH, szDir);
		lstrcat(szDir, _T("\\*.*"));
		hFile = FindFirstFile(szDir, &wf);
		if (hFile == INVALID_HANDLE_VALUE)
			return E_FAIL; // 用户没有 c:\ 驱动器
		FindClose(hFile);// szDir 已获得表名称

		DBID dbid;
		memset(&dbid, 0, sizeof(DBID));
		dbid.uName.pwszName = T2OLE(szDir);
		dbid.eKind = DBKIND_NAME;
		return InitFromRowset < _RowsetArrayType > (m_rgRowData, &dbid, NULL, m_spUnkSite, pcRowsAffected);
	}
	DBSTATUS GetDBStatus(CSimpleRow*, ATLCOLUMNINFO* pInfo)
	{
		switch(pInfo->iOrdinal)
		{
		case 1:
		case 2:
		case 19:
		case 20:
		case 22:
		case 23:
		case 25:
		case 26:
			return DBSTATUS_S_ISNULL;
		default:
			return DBSTATUS_S_OK;
		}

	}
};

class CTxtProviderSessionPTSchemaRowset : 
	public CSchemaRowsetImpl< CTxtProviderSessionPTSchemaRowset, CPROVIDER_TYPERow, CTxtProviderSession>
{
public:
BEGIN_PROPSET_MAP(CTxtProviderSessionPTSchemaRowset)
	BEGIN_PROPERTY_SET(DBPROPSET_ROWSET)
		PROPERTY_INFO_ENTRY(IAccessor)
		PROPERTY_INFO_ENTRY(IColumnsInfo)
		PROPERTY_INFO_ENTRY(IConvertType)
		PROPERTY_INFO_ENTRY(IRowset)
		PROPERTY_INFO_ENTRY(IRowsetIdentity)
		PROPERTY_INFO_ENTRY(IRowsetInfo)
		PROPERTY_INFO_ENTRY(CANFETCHBACKWARDS)
		PROPERTY_INFO_ENTRY(CANHOLDROWS)
		PROPERTY_INFO_ENTRY(CANSCROLLBACKWARDS)
		PROPERTY_INFO_ENTRY_VALUE(MAXOPENROWS, 0)
		PROPERTY_INFO_ENTRY_VALUE(MAXROWS, 0)
	END_PROPERTY_SET(DBPROPSET_ROWSET)
END_PROPSET_MAP()

	HRESULT Execute(LONG* pcRowsAffected, ULONG, const VARIANT*)
	{
		return S_OK;
	}
};