定义:
_ConnectionPtr m_pAccess;数据库也没有问题
rt
采用注释部分代码完全没问题
pRecord = theApp.m_pAccess->Execute(_bstr_t("select * from user_base"),&RecordsAffected,adCmdText);
//pRs->AddNew();
//pRs->PutCollect(L"userid", 2);
//pRs->PutCollect("actiondes", "坑爹");
//pRs->PutCollect("actiontime", (_variant_t)m_date);
//pRs->Update();
而采用->execute()就会在如下comip.h部分中断
Interface* operator->() const
{
if (m_pInterface == NULL) {
_com_issue_error(E_POINTER);
} return m_pInterface;
}
求解,c功底不够扎实,请高手帮忙解答
_ConnectionPtr m_pAccess;数据库也没有问题
rt
采用注释部分代码完全没问题
pRecord = theApp.m_pAccess->Execute(_bstr_t("select * from user_base"),&RecordsAffected,adCmdText);
//pRs->AddNew();
//pRs->PutCollect(L"userid", 2);
//pRs->PutCollect("actiondes", "坑爹");
//pRs->PutCollect("actiontime", (_variant_t)m_date);
//pRs->Update();
而采用->execute()就会在如下comip.h部分中断
Interface* operator->() const
{
if (m_pInterface == NULL) {
_com_issue_error(E_POINTER);
} return m_pInterface;
}
求解,c功底不够扎实,请高手帮忙解答
前面theApp干什么.
m_pAccess->Execute不就行了.
改这样
_ConnectionPtr m_pAccess(__uuidof(Connection));
下面是使用Xproer.OleDb对数据库进行操作的示例:#include "stdafx.h"
#include "XproerDataDef.h"
#include "OleDb/OleDbCommand.h"
#include "OleDb/OleDbConnection.h"
#include "OleDb/OleDbDataReader.h"
#include "OleDb/DataTable.h"
#include "OleDb/DataRow.h"
#include "OleDb/DataValue.h"using namespace Xproer::OleDb;//获取DataTable的示例
void ADODataTable(OleDbCommand& cmd)
{
int count = 0;
cmd.ExecuteScalar(L"select count(*) from xdb_news",count);
auto_ptr<DataTable> table;
table.reset(cmd.ExecuteDataTable(L"select top 10 IsTop from xdb_news")); size_t rowCount = table->GetRowsCount();
for (int i = 0 ; i < rowCount ; ++i)
{
DataRow* row = table->GetRow(i);
DataValue* val = row->GetCel(0);
printf("时间:%d \r\n", val->ToBoolean() );
}
}//使用OleDbDataReader快速读取数据的示例
void ADORead(OleDbCommand& cmd)
{
OleDbDataReader* r = cmd.ExecuteReader(L"select ProductPrice from xdb_news");
USES_CONVERSION;
wstring title;
while(r->Read())
{
//r->GetString(0,title);
//printf("标题:%s \r\n",W2A(title.c_str()));
printf("ID:%f \r\n", r->GetFloat(0) );
}
r->Close();
}//通过变量向数据库安全添加数据的示例
void ADOAdd(OleDbCommand& cmd)
{
cmd.SetCommandText(L"insert into xdb_about(VDouble) values(@VDouble)");
cmd.AddDoubleParam(L"@VDouble",125022.3180); cmd.ExecuteNonQuery();
}//高性能向数据库插入数据的示例
void ADOParam(OleDbCommand& cmd)
{
cmd.SetCommandText(L"delete from xdb_news where ID=@ID;");
cmd.AddInt32Param(L"@ID",886);
cmd.SetPrepared(true); _variant_t index = (short)0;
_ParameterPtr param = cmd.GetCommand()->Parameters->GetItem(index);
param->Value = 887;
cmd.ExecuteNonQuery();
param->Value = 888;
cmd.ExecuteNonQuery();
param->Value = 889;
cmd.ExecuteNonQuery();
param->Value = 890;
cmd.ExecuteNonQuery();
param->Value = 891;
cmd.ExecuteNonQuery();
}//向数据库添加实数的示例
void NumericScaleX(OleDbCommand& cmd)
{
OleDbDataReader* r = cmd.ExecuteReader(L"select ProductPrice from xdb_news");
_RecordsetPtr& rs = r->GetRecordsetPtr();
rs->MoveFirst(); _variant_t vi = (short)0;
FieldPtr fd = rs->Fields->GetItem(vi);
unsigned char numeri = fd->GetNumericScale();
unsigned char precision = fd->GetPrecision(); printf("GetNumericScale:%d\r\n", fd->GetNumericScale() );
printf("GetPrecision:%d\r\n", fd->GetPrecision() );
printf("Value:%f\r\n", (float)fd->Value );
r->Close();
}int _tmain(int argc, _TCHAR* argv[])
{
::CoInitialize(NULL);
OleDbConnection con;
con.SetAccessConStr(L"F:\\vc9\\adoDemo\\Debug\\db.mdb");
con.Open(); OleDbCommand cmd(&con); ADORead(cmd);
con.Close(); ::CoUninitialize();
//printf("总数:%d",count);
system("pause");
return 0;
}
http://blog.csdn.net/xianglitian/article/details/5617173