问获取Qt应用程序中可用ODBC数据源的列表

EN

#include <windows.h>
#include <tchar.h>
#include <iostream>
#include <sql.h>
#include <sqlext.h>
#include <sqlucode.h>

#define BUFF_LENGTH 1024

int _tmain(int argc, _TCHAR* argv[])
{
    // Get an Environment handle
    SQLHENV hEnv = SQL_NULL_HENV;
    // SQLAllocHandle() is for ODBC 3.x
    SQLRETURN ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hEnv);
    // If you do not have ODBC 3.x try with the old version:
    // SQLRETURN ret = SQLAllocEnv(&hEnv);
    if(!SQL_SUCCEEDED(ret))
    {
        std::wcerr << L"No handle" << std::endl;
        return 1;
    }
    // set odbc version (this is required, if not set we get 'function sequence error')
    ret = SQLSetEnvAttr(hEnv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER) SQL_OV_ODBC3_80, NULL);
    if(!SQL_SUCCEEDED(ret))
    {
        std::wcerr << L"Failed to set version" << std::endl;
        SQLFreeHandle(SQL_HANDLE_ENV, hEnv);
        return 1;
    }

    // Query sources
    SQLWCHAR nameBuffer[BUFF_LENGTH];
    SQLWCHAR descBuffer[BUFF_LENGTH];
    SQLSMALLINT nameBufferLength = 0;
    SQLSMALLINT descBufferLength = 0;
    ret = SQLDataSources(hEnv, SQL_FETCH_FIRST, nameBuffer, BUFF_LENGTH, &nameBufferLength, descBuffer, BUFF_LENGTH, &descBufferLength);
    if(ret == SQL_NO_DATA)
    {
        // no entries found
        std::wcout << L"No DSN found" << std::endl;
    }
    else if(SQL_SUCCEEDED(ret))
    {
        do
        {
            // do something with the name available in nameBuffer now..
            std::wcerr << L"Name: " << nameBuffer << std::endl;
            // then fetch the next record
            ret = SQLDataSources(hEnv, SQL_FETCH_NEXT, nameBuffer, BUFF_LENGTH, &nameBufferLength, descBuffer, BUFF_LENGTH, &descBufferLength);
        } while(ret == SQL_SUCCESS || ret == SQL_SUCCESS_WITH_INFO);
    }
    else
    {
        SQLSMALLINT recNr = 1;
        SQLRETURN ret = SQL_SUCCESS;
        while(ret == SQL_SUCCESS || ret == SQL_SUCCESS_WITH_INFO)
        {
            SQLWCHAR errMsg[SQL_MAX_MESSAGE_LENGTH + 1];
            SQLWCHAR sqlState[5 + 1];
            errMsg[0] = 0;
            SQLINTEGER nativeError;
            SQLSMALLINT cb = 0;
            ret = SQLGetDiagRec(SQL_HANDLE_ENV, hEnv, recNr, sqlState, &nativeError, errMsg, SQL_MAX_MESSAGE_LENGTH + 1, &cb);
            if(ret == SQL_SUCCESS || ret == SQL_SUCCESS_WITH_INFO)
            {
                std::wcerr << L"ERROR; native: " << nativeError << L"; state: " << sqlState << L"; msg: " << errMsg << std::endl;
            }
            ++recNr;
        }
        std::wcerr << L"Failed";

        SQLFreeHandle(SQL_HANDLE_ENV, hEnv);
        return 1;
    }


    SQLFreeHandle(SQL_HANDLE_ENV, hEnv);
    return 0;
}