www.pudn.com > odbc_class.rar > ODBCSet.h

// ODBCSet.h: interface for the CODBCSet class. 
// 
////////////////////////////////////////////////////////////////////// 
 
#if !defined(AFX_ODBCSET_H__B87857A0_A997_48BD_9142_AD86790D7426__INCLUDED_) 
#define AFX_ODBCSET_H__B87857A0_A997_48BD_9142_AD86790D7426__INCLUDED_ 
 
#include "MyODBC.h"	// Added by ClassView 
#if _MSC_VER > 1000 
#pragma once 
#endif // _MSC_VER > 1000 
 
typedef struct  
{ 
	char	name[256]; 
	short	datatype; 
	int	maxlength; 
} COL_DATAFMT_ODBC;//每一字段的描述，名称，类型，长度 
 
typedef struct 
{ 
	char*	value; 
	long *	valuelen; 
}COL_DATA_ODBC;	//每一列的内容,一个结构代表了一列的所有数据 
 
typedef struct   
{ 
	char* value; 
	long length; 
}CELL_DATA_ODBC;//每个单元格的内容 
 
class CODBCSet   
{ 
	public: 
	int m_cols;			//查询返回列数 
	COL_DATAFMT_ODBC *m_coldatafmt; 
	COL_DATA_ODBC* m_coldata; 
public: 
	CODBCSet(); 
	virtual ~CODBCSet(); 
	int const GetCols(); 
	void Empty(); 
	COL_DATAFMT_ODBC GetColInfo(int i); 
	BOOL IsEmpty(); 
	class Row  
	{ 
		CODBCSet& m_recordset; 
		int m_iRow; 
	public: 
		inline Row(CODBCSet& recordset, int iRow):m_recordset(recordset), m_iRow(iRow){} 
	 
		inline const CELL_DATA_ODBC operator[](int iCol)const  
		{ return m_recordset( iCol, m_iRow);} 
		 
		inline const CELL_DATA_ODBC operator[](LPCSTR strColName)const  
		{ return m_recordset(strColName, m_iRow);} 
		 
	};//用Row来表示CRecordSet中的每一行， 
 
	inline const Row operator[](int iRow) 
	{ return Row(*this, iRow); }//得到批定的行 
 
	inline const CELL_DATA_ODBC operator ()(int iCol, int iRow = 0)const//得到指定行和列的值 
	{ 
		CELL_DATA_ODBC celldata; 
		celldata.value = m_coldata[iCol].value + iRow*m_coldatafmt[iCol].maxlength; 
		// oracle: 
		//              indicator == -1, The selected value is null, and the value of  
		//                                         the output variable is unchanged. 
		//              indicator  == 0, Oracle assigned an intact value to the host variable. 
		//              indicator  > 0 ,    The length of the item is greater than the length of  
		//                                         the output variable; the item has been truncated. The positive value  
		//                                         returned in the indicator variable is the actual length before truncation. 
		 
		celldata.length = m_coldata[iCol].valuelen[iRow]; 
		celldata.value[celldata.length] = 0; 
		return celldata; 
	} 
 
	inline const CELL_DATA_ODBC operator ()(LPCSTR strColName, int iRow = 0)const  
	{ 
		CELL_DATA_ODBC celldata; 
		int iCol; 
		for( iCol = 0; iCol < m_cols; iCol++  ) 
		{ 
			if( strcmp(m_coldatafmt[iCol].name, strColName)== 0 ) 
			{ 
				break; 
			} 
		} 
 
		if( iCol >= m_cols ) 
		{ // not found column according its name 
			celldata.value = 0;  celldata.length = 0; 
		} 
		else  
		{			 
			celldata.value = m_coldata[iCol].value + iRow*m_coldatafmt[iCol].maxlength; 
 
			celldata.length = m_coldata[iCol].valuelen[iRow]; 
 
			celldata.value[celldata.length] = 0; 
		} 
		return celldata; 
	} 
 
	 
 
}; 
 
#endif // !defined(AFX_ODBCSET_H__B87857A0_A997_48BD_9142_AD86790D7426__INCLUDED_)