Visual Studio C++连接到DB2
问题描述:
我正在尝试使用数据库编写C++程序 - IBM DB2 Express-C。另外,我使用Visual Studio 2015.通过IBM OLE DB Provider for DB2,我的Visual Studio成功连接到DB2。我可以看到表和一切OK:Visual Studio C++连接到DB2
然后创建新的C++程序中,我成功地连接几个头文件,一些从他们身上我在DB2目录中,例如sqlcli1.h
#pragma once
#include "targetver.h"
#include <stdio.h>
#include <tchar.h>
#include <stdlib.h>
#include <string.h>
#include <sqlcli1.h>
#include <windows.h>
以下是主程序的代码。其中我正尝试连接到成功连接到Visual Studio的数据库。
#include "stdafx.h"
int main()
{
SQLHENV henv;
SQLHDBC hdbc;
SQLHSTMT hstmt;
SQLRETURN retcode;
SQLCHAR * OutConnStr = (SQLCHAR *)malloc(255);
SQLSMALLINT * OutConnStrLen = (SQLSMALLINT *)malloc(255);
// Allocate environment handle
retcode = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
// Set the ODBC version environment attribute
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) {
// Allocate connection handle
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) {
retcode = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
// Connect to data source
retcode = SQLConnect(hdbc, (SQLWCHAR*) "DATABASE=SAMPLE;HOSTNAME=localhost", SQL_NTS, (SQLWCHAR*) "db2admin", SQL_NTS, (SQLWCHAR*) "password", SQL_NTS);
if (retcode != SQL_SUCCESS) {
printf(">--- Error while connecting to database:");
printf("SQLConnect: %d\n", retcode);
}
// Allocate statement handle
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) {
retcode = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);
printf("\nAllocate Connection handle successfully.");
// Process data
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) {
SQLFreeHandle(SQL_HANDLE_STMT, hstmt);
}
SQLDisconnect(hdbc);
}
SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
}
SQLFreeHandle(SQL_HANDLE_ENV, henv);
}
system("pause");
return 0;
}
在编译时没有错误,但无法连接到数据库。当程序执行到达块时。
// Connect to data source
retcode = SQLConnect(hdbc, (SQLWCHAR*) "DATABASE=SAMPLE;HOSTNAME=localhost", SQL_NTS, (SQLWCHAR*) "db2admin", SQL_NTS, (SQLWCHAR*) "password", SQL_NTS);
if (retcode != SQL_SUCCESS) {
printf(">--- Error while connecting to database:");
printf("SQLConnect: %d\n", retcode);
}
我看到> ---错误,同时连接到数据库:的SQLConnect:-2 这是什么意思?我在做什么是错误的?我也试过了:
retcode = SQLConnect(hdbc, (SQLWCHAR*) "SAMPLE", SQL_NTS, (SQLWCHAR*) "db2admin", SQL_NTS, (SQLWCHAR*) "password", SQL_NTS);
但它也行不通。可能是第二个参数应该看起来像其他方式?
改变 我想利用这个功能SQLGetDiagRec的我创建了一些变量
SQLWCHAR SqlState[6], SQLStmt[100], Msg[SQL_MAX_MESSAGE_LENGTH];
SQLINTEGER NativeError;
SQLSMALLINT i, MsgLen;
SQLRETURN rc1, rc2;
我也改变我的连接块
// Connect to data source
retcode = SQLConnect(hdbc, (SQLWCHAR*) "SAMPLE", SQL_NTS, (SQLWCHAR*) "db2admin", SQL_NTS, (SQLWCHAR*) "password", SQL_NTS);
if (retcode != SQL_SUCCESS) {
printf(">--- Error while connecting to database:");
printf("SQLConnect: %d\n", retcode);
if ((retcode == SQL_SUCCESS_WITH_INFO) || (retcode == SQL_ERROR)) {
// Get the status records.
i = 1;
while ((rc2 = SQLGetDiagRec(SQL_HANDLE_STMT, hdbc, i, SqlState, &NativeError,
Msg, sizeof(Msg), &MsgLen)) != SQL_NO_DATA) {
cout << SqlState;
cout << i;
cout << NativeError;
cout << Msg;
i++;
}
}
}
但一切都没有改变。有人有什么主意吗?
我试了一下**改变的问题**,但功能'SQLGetDiagRec的()'不打印任何东西。 – Vladimir