C++ access数据库中字段信息获取

2013-03-10

void CDataControl::GetFieldNameCn(const CString& sTableName,CADORecordset* pAdoAccess,const CString& sNameEn, CString& sNameCn)
{
	SAFEARRAY   FAR*   psa   =   NULL; 
	SAFEARRAYBOUND   rgsabound; 
	_variant_t     var; 
	_variant_t     Array; 
	rgsabound.lLbound   =   0; 
	rgsabound.cElements   =   4; 
	psa   =   SafeArrayCreate(VT_VARIANT,   1,   &rgsabound); 
	var.vt   =   VT_EMPTY; 
	long   ix; 
	ix   =   0; 
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	ix=   1; 
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	ix   =   2; 
	var.vt   =   VT_BSTR; 
	var.bstrVal   =sTableName.AllocSysString();		//表名  sTableName 
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	var.vt   =   VT_BSTR; 
	ix   =   3; 
	var.bstrVal   =sNameEn.AllocSysString();//字段名
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	Array.vt   =   VT_ARRAY|VT_VARIANT; 
	Array.parray   =   psa;   
 
	pAdoAccess->m_pRecordset   =   pAdoAccess->GetActiveConnection()->OpenSchema(adSchemaColumns,&Array);  
 
	Field *fd = pAdoAccess->m_pRecordset->Fields->GetItem("DESCRIPTION");
	if (fd->GetValue().vt != VT_NULL)
	{
		_bstr_t  column_discription = fd->Value;
		CString sNote;
		sNote.Format(_T("%s"), (LPCTSTR)column_discription);
		sNameCn =  (LPCTSTR)column_discription;
	}
	else
	{
		sNameCn = sNameEn;
	}
}
 
BOOL CDataControl::GetFileNULL(const CString& sTableName,const CString& sFileNameEN,CString& sFileNameCN,CADORecordset* pAdoAccess,BOOL& ISNullSet, int& OrdinalPostion)
{
	SAFEARRAY   FAR*   psa   =   NULL; 
	SAFEARRAYBOUND   rgsabound; 
	_variant_t     var; 
	_variant_t     Array; 
	rgsabound.lLbound   =   0; 
	rgsabound.cElements   =   4; 
	psa   =   SafeArrayCreate(VT_VARIANT,   1,   &rgsabound); 
	var.vt   =   VT_EMPTY; 
	long   ix; 
	ix   =   0; 
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	ix=   1; 
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	ix   =   2; 
	var.vt   =   VT_BSTR; 
	var.bstrVal   =sTableName.AllocSysString();		//表名  sTableName 
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	var.vt   =   VT_BSTR; 
	ix   =   3; 
	var.bstrVal   =sFileNameEN.AllocSysString();//字段名
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	Array.vt   =   VT_ARRAY|VT_VARIANT; 
	Array.parray   =   psa;   
 
	pAdoAccess->m_pRecordset   =   pAdoAccess->GetActiveConnection()->OpenSchema(adSchemaColumns,&Array);  
	//IS_NULL = 1 表示字段可以为空   0 表示必填
	ISNullSet = (pAdoAccess->m_pRecordset->Fields->GetItem("IS_NULLABLE")->Value.boolVal == -1)?TRUE:FALSE;//是否允许为空
	_bstr_t  column_name = pAdoAccess->m_pRecordset->Fields->GetItem("COLUMN_NAME")->Value;//字段名
	OrdinalPostion = pAdoAccess->m_pRecordset->Fields->GetItem("ORDINAL_POSITION")->Value;//字段序号
 
	Field *fd = pAdoAccess->m_pRecordset->Fields->GetItem("DESCRIPTION");
	if (fd->GetValue().vt != VT_NULL)
	{
		_bstr_t  column_discription = fd->Value;
		CString sNote;
		sNote.Format(_T("%s"), (LPCTSTR)column_discription);
		sFileNameCN =  (LPCTSTR)column_discription;
	}
	else
	{
		sFileNameCN = sFileNameEN;
	}
 
	//int  NUMERIC_PRECISION = m_pRecordset->Fields->GetItem("NUMERIC_PRECISION")->Value;
	//int  NUMERIC_SCALE = m_pRecordset->Fields->GetItem("NUMERIC_SCALE")->Value;
 
 
	return TRUE;
}
 
BOOL CDataControl::GetFilePkName(const CString& sTableName,std::vector<CString>& sPkName,CADORecordset* pAdoAccess)
{
	SAFEARRAY   FAR*   psa   =   NULL; 
	SAFEARRAYBOUND   rgsabound; 
	_variant_t     var; 
	_variant_t     Array; 
	rgsabound.lLbound   =   0; 
	rgsabound.cElements   =   3; 
	psa   =   SafeArrayCreate(VT_VARIANT,   1,   &rgsabound); 
	var.vt   =   VT_EMPTY; 
	long   ix; 
	ix   =   0; 
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	ix=   1; 
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	ix   =   2; 
	var.vt   =   VT_BSTR; 
	var.bstrVal   =sTableName.AllocSysString();		//表名  sTableName 
	SafeArrayPutElement(psa,   &ix,   &var); 
 
	Array.vt   =   VT_ARRAY|VT_VARIANT; 
	Array.parray   =   psa;   
 
	pAdoAccess->m_pRecordset   =   pAdoAccess->GetActiveConnection()-> OpenSchema(adSchemaPrimaryKeys,&Array);  //adSchemaColumns
 
	while(!pAdoAccess->IsEOF())
	{
		_bstr_t  column_name = pAdoAccess->m_pRecordset->Fields->GetItem("COLUMN_NAME")->Value;
		_bstr_t   column_PK=   pAdoAccess->m_pRecordset-> Fields-> GetItem( "PK_NAME")-> Value; 
 
		sPkName.push_back((LPCTSTR)column_name);
		pAdoAccess->MoveNext();
	}
 
	return TRUE;
}

阅读全文

C++ 树层级存储

Peach

2013-03-09

用了一个map来记录所有的层级关系,然后从root找起,依次找出所有的节点…

// 用的是tinyXML读取
 
BOOL CXmlRead::ReadGroupInfo( std::map<CString, std::vector<std::pair<CString, BOOL>>> &mapGroup )
{
    // 载入文件
    TiXmlDocument *doc = new TiXmlDocument(PATH);
    if (!doc->LoadFile())
    {
        delete doc;
        return FALSE;
    }
 
    // 获取根节点
    TiXmlElement *pRoot = doc->FirstChildElement(_T("TableGroup"));
    ASSERT(pRoot);
    if (pRoot == NULL)
    {
        delete doc;
        return FALSE;
    }
 
    mapGroup.clear();
 
    std::vector<std::pair<CString, BOOL>> vecTable;
    TiXmlElement *pNode = dynamic_cast<TiXmlElement *>(pRoot->FirstChildElement());
    while (pNode != NULL)
    {
        // 节点属性
        CString strSubName = pNode->Attribute(_T("Name"));
        vecTable.push_back(std::make_pair(strSubName, TRUE));
        ASSERT(_T("Group") == (CString)(pNode->Value()));
 
        if(!ReadNode(pNode, mapGroup))
        {
            return FALSE;
        }
 
        // 下一关键字节点
        pNode = dynamic_cast<TiXmlElement *>(pNode->NextSiblingElement());
    }
    mapGroup[_T("ROOT")] = vecTable;
 
    delete doc;
    return TRUE;
}
 
BOOL CXmlRead::ReadNode(TiXmlElement *pNode, std::map<CString, std::vector<std::pair<CString, BOOL>>> &mapGroup)
{
    // 每次添加的新节点应该是之前没有出现过的,否则会死循环
    CString strNodeName = pNode->Attribute(_T("Name"));
    if(mapGroup.end() != mapGroup.find(strNodeName)) return FALSE;
 
    std::vector<std::pair<CString, BOOL>> vecTable;
    TiXmlElement *pSubNode = dynamic_cast<TiXmlElement *>(pNode->FirstChildElement());
    while (pSubNode != NULL)
    {
        // 节点名
        CString strSub = pSubNode->Value();
        // 节点属性
        CString strSubName = pSubNode->Attribute(_T("Name"));
 
        if(_T("Group") == strSub)
        {
            vecTable.push_back(std::make_pair(strSubName, TRUE));
            if(!ReadNode(pSubNode, mapGroup))
            {
                return FALSE;
            }
        }
        else if(_T("Table") == strSub)
        {
            vecTable.push_back(std::make_pair(strSubName, FALSE));            
        }
 
        // 下一关键字节点
        pSubNode = dynamic_cast<TiXmlElement *>(pSubNode->NextSiblingElement());
    }
 
    mapGroup[strNodeName] = vecTable;
    return TRUE;
}

其实vector里面的bool是可以不要的,最初加这个只是为了区分树节点和叶节点…

阅读全文

C++ 获取某目录下的全部文件

Peach

2013-03-08

特别需要注意的是,每个文件夹下有.和..两个文件夹分别代表当前目录和上级目录(根目录的..代表当前目录)…IsDot就是用来检测当前是不是.或..的函数

阅读全文