C++操作mysql方法总结（2）

#include <Windows.h>
#include <iostream>
#include <iomanip>
#include <sql.h>
#include <odbcss.h>
#include <sqlext.h>
#define MAXBUFLEN   255 
#define MaxNameLen  20

#import "c:\program files\common files\system\ado\msado15.dll" no_namespace rename("EOF", "adoEOF")

SQLHENV  henv = SQL_NULL_HENV;//定义环境句柄
SQLHDBC  hdbc1 = SQL_NULL_HDBC;//定义数据库连接句柄     
SQLHSTMT  hstmt1 = SQL_NULL_HSTMT;//定义语句句柄

using namespace std;
int main()
{
    RETCODE retcode;//错误返回码
    retcode = SQLAllocHandle(SQL_HANDLE_ENV, NULL, &henv);
    if (retcode < 0)//错误处理
    {
        cout << "allocate ODBC Environment handle errors." << endl;
        return -1;
    }
    retcode = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION,
        (SQLPOINTER)SQL_OV_ODBC3, SQL_IS_INTEGER);
    if (retcode < 0) //错误处理
    {
        cout << "the  ODBC is not version3.0 " << endl;
        return -1;
    }
    retcode = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc1);
    if (retcode < 0) //错误处理
    {
        cout << "allocate ODBC connection handle errors." << endl;
        return -1;
    }

    char* szDSN = "MySqlODBC";//添加数据源时，为其起的名字
    char* szUID = "root";
    char* szAuthStr = "123456";

    retcode = SQLConnect(hdbc1,
                        (SQLCHAR*)szDSN, 
                        (SWORD)strlen(szDSN), 
                        (SQLCHAR*)szUID, 
                        (SWORD)strlen(szUID), 
                        (SQLCHAR*)
                        szAuthStr,
                        (SWORD)strlen(szAuthStr));

    if (retcode < 0) //错误处理
    {
        cout << "connect to  ODBC datasource errors." << endl;
        return -1;
    }

    retcode = SQLAllocHandle(SQL_HANDLE_STMT, hdbc1, &hstmt1);
    if (retcode < 0) 
    {
        cout << "allocate ODBC statement handle errors." << endl;
        return -1;
    }
    retcode = SQLExecDirect(hstmt1, (SQLCHAR*)"SElECT *  FROM book", SQL_NTS);
    if (retcode < 0)
    {
        cout << "Executing statement  throught ODBC  errors." << endl;
        return -1;
    }
    SQLCHAR      bookname[MaxNameLen + 1];
    SQLCHAR         size[MaxNameLen + 1];
    SQLLEN         columnLen = 0;

    retcode = SQLBindCol(hstmt1, 2, SQL_C_CHAR, bookname, MaxNameLen, &columnLen);
    retcode = SQLBindCol(hstmt1, 3, SQL_C_CHAR, size, MaxNameLen, &columnLen);
    while ((retcode = SQLFetch(hstmt1)) != SQL_NO_DATA)
    {
        cout <<setw(9) <<"BookName:" << bookname << endl;
        cout << setw(9) << "Size:" << size << endl;
    }
    system("pause");
}

#include "stdafx.h"
#include "afxdb.h"
#include <iostream>
#include <iomanip>
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
    CDatabase db;

    if (!db.IsOpen())//判断数据库是否已经被打开
    {

        BOOL bflag=     db.Open(NULL, FALSE, FALSE, _T("ODBC;DSN=MySqlODBC;UID=root;PWD=123456"));    
        if (!bflag)
        {
            cout << "ERROR" << endl;
        }
    }

    CRecordset rs(&db);
    CString str;
    str.Format(L"select * from book");
    try
    {
        rs.Open(CRecordset::forwardOnly, (L"%s", str));
        short nFields = rs.GetODBCFieldCount();
        while (!rs.IsEOF())
        {

            CDBVariant varValue;
            rs.GetFieldValue(L"bookname", varValue);
            cout << setw(9) << "BookName:" << *varValue.m_pstringA << endl;
            rs.GetFieldValue(L"size", varValue);
            cout << setw(9) << "Size:" << *varValue.m_pstringA << endl;
            rs.MoveNext();
        }
    }
    catch (...)
    {
        cout << "ERRPR" << endl;
    }

    db.Close();
    system("pause");
}