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我的主題對我來說有點愚蠢和複雜。我試圖與Access 2007數據庫進行非常簡單的連接,但連接永遠不會發生。我試圖看看SQLGetDiagRec()會發生什麼,但是執行SQLGetDiagRec()時程序崩潰。我對C++並沒有太多的瞭解,所以在過去的幾天裏我被困在這裏。任何幫助將不勝感激。我正在使用Visual C++ 2008.無法使用C++連接到Access數據庫
編輯:將字符集從Unicode更改爲多字節後,我能夠執行SQLGetDiagRec。然後,我將我的兩個指針從int和char改爲SQLSMALLINT和SQLCHAR,並且它的工作原理。感謝大家的頭。
#include "stdafx.h"
#include <windows.h>
#include <conio.h>
#include <iostream>
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>
#include <stdio.h>
#include <stdlib.h>
int main(){
char szDSN[256] = "DRIVER={Microsoft Access Driver (*.mdb, *.accdb)};DSN='Hospital_mdb';DBQ=C:\\Hospital.mdb;";
SQLHANDLE EnvHandlePtr;
SQLHANDLE ConHandle;
SQLHANDLE StmtHandle;
SQLRETURN rc;
SQLSMALLINT iConnStrLength2Ptr; // Changing from int iConnStrLength2Ptr;
SQLCHAR szConnStrOut[256]; //changing from char szConnStrOut[256];
SQLCHAR SQLState[6], Msg[SQL_MAX_MESSAGE_LENGTH];
SQLINTEGER NativeError;
SQLSMALLINT MsgLen;
if ((rc = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &EnvHandlePtr)) == SQL_SUCCESS){
printf("Environment Set!");
if((rc = SQLSetEnvAttr(EnvHandlePtr, SQL_ATTR_ODBC_VERSION,
(SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER))==SQL_SUCCESS){
printf("Driver Set!");
if ((rc = SQLAllocHandle(SQL_HANDLE_DBC, EnvHandlePtr, &ConHandle))==SQL_SUCCESS){
printf("Allocation Done!");//**so far, so good, but then the connection doesn't happen**
rc = SQLDriverConnect(ConHandle, NULL, (SQLWCHAR*)szDSN,
SQL_NTS, (SQLWCHAR*) szConnStrOut, 0, (SQLSMALLINT*) iConnStrLength2Ptr, SQL_DRIVER_NOPROMPT);
if (rc == SQL_SUCCESS){
//if ((rc = SQLConnect(ConHandle, (SQLWCHAR*)szDSN, SQL_NTS, (SQLWCHAR*)"", SQL_NTS, (SQLWCHAR*)"", SQL_NTS))== SQL_SUCCESS){
printf("Connection Done");
}//end of Connection clause
else{
SQLGetDiagRec(SQL_HANDLE_DBC, ConHandle, 1, (SQLWCHAR*)SQLState, &NativeError, (SQLWCHAR*)Msg, sizeof(Msg), &MsgLen);
printf("Connection Failed\n%s", Msg);
}
SQLDisconnect(ConHandle);
}//end of Connection Allocation clause
SQLFreeHandle(SQL_HANDLE_DBC, ConHandle);
}//end of Driver clause
SQLFreeHandle(SQL_HANDLE_ENV, EnvHandlePtr);
}//end of Enviroment clause
_getch();
}//end of main
Lol'(SQLWCHAR *)szDSN' – 2011-04-12 12:58:52
基本上我因爲配置錯誤而讓他們像這樣流氓。在將項目的字符集從Unicode更改爲Multibyte(並正確聲明變量)之後,我開始工作了。但問題是我仍然無法連接到數據庫,但我可以打印錯誤,這是一個「無效的字符串或緩衝區長度」。我發現這意味着這裏的某個地方存在着實際問題:'rc = SQLConnect(ConHandle,szDSN,SQL_NTS,(SQLCHAR *)「」,SQL_NTS,(SQLCHAR *)「」,SQL_NTS)也找到這一個。 – Iraklis 2011-04-12 16:50:59
儘量不要忽視「從來不是錯誤」的評論。當您使用dbases時,Unicode是*必需*。 – 2011-04-12 22:01:08