thanks , but it can not be reduced

wuhuaiji

like avg(),sum(),and so on i would like to see the source files where exist these files? thanks a lot:-D

wuhuaiji

hello everyone :) i define a datatype float, but when i write a value, for exsample '1.123',to the table, then i find that the value in the table changed to '1.123999999999999', what's the problem? thanks a lot :-D

wuhuaiji

i have a problem, that i want to write a function like avg(),count()..... but the parameter i want to pass to the function is a row-name, for exsample: i have a table, which includes 1000 values of temperature, i want to calculate the variance of all the 1000 values.

wuhuaiji

thanks a lot first, i am a newbie, ;P then, i just want draw a curve, which can move now i have got many friends' help, thanks for all of your answer and i think maybe i have found the solution indeed, the question is a little problem, the big problem is that i am fresh in VC

wuhuaiji

thanks i have googled, and now i know how to draw a static curve but i want to draw a dynamic curve, which can move smoothly with time going

wuhuaiji

hello thanks for your answer my problem is, how to make the curve move smoothly? it move from right to left with time going

wuhuaiji

i want to lern to draw a dynamic curve,but do not know how to do; is there any good Activecontrol or methode, my idea is, continuesly get data from a database or by some way else, then draw them on a picture, the curve should be dynamic. thanks a lot

wuhuaiji

thanks a lot:)

wuhuaiji

i write like this: SELECT * FROM TB_ANGEL ORDER BY angel ASC but i want not only query by order, i also want update the table by order thanks a lot:)

wuhuaiji

when i do write the following: m_pRecordset->Open("CREATE TABLE MY10151109(ID INT,Hex_Fangwei TEXT,Hex_FuYang TEXT,Hex_QingXie TEXT)", theApp.m_pConnection.GetInterfacePtr(), adOpenDynamic, adLockOptimistic, adCmdText); it runs OK; but when i do it like this: CString mstr; mstr.Format("CREATE TABLE '%s'(ID INT,Hex_Fangwei TEXT,Hex_FuYang TEXT,Hex_QingXie TEXT)",TB_Name); m_pRecordset->Open(mstr.AllocSysString（）， theApp.m_pConnection.GetInterfacePtr(), adOpenDynamic, adLockOptimistic, adCmdText); appear runtime error who could tell me why , and what should i do?

wuhuaiji

excuse me but i have found that when i do nothing to the database in a WM_TIMER function, there is no error, but just if i do something, for example: void CSerialRecieveDlg::OnTimer(UINT nIDEvent){ CString str; CCreateName Dlg; CString TB_Name; TB_Name=Dlg.m_TableName; str.Format("SELECT * FROM "); str+=TB_Name; try { //先关闭已经打开的记录集对象 m_pRecordset->Close(); //根据新的Sql查询语句，重新打开记录集对象 m_pRecordset->Open(str.AllocSysString(), theApp.m_pConnection.GetInterfacePtr(), adOpenDynamic, adLockOptimistic, adCmdText); } catch(_com_error *e) { AfxMessageBox(e->ErrorMessage()); } m_pRecordset->MoveNext(); CDialog::OnTimer(nIDEvent); } there is a runtime error, The problem is that i do not know it is a database problem or a C++ problem??

wuhuaiji

thanks a lot:)

wuhuaiji

thanks a lot:)

wuhuaiji

it has no businiss with the timer, because when i change it to 2second, it also appear error： （step debug) unhandled exception in SerialRecieve.exe(KERNEL32.DLL):0xE06D7363:Microsoft C++ EXCEPTION no matter where the error appears, it appears always in the CSerialRecieveDlg::OnTimer(UINT nIDEvent)

wuhuaiji

get data from three different tables , and then do something , and then show them, look the flowing: void CSerialRecieveDlg::OnTimer(UINT nIDEvent) { // TODO: Add your message handler code here and/or call default CString strSql; // int m=atoi(m_strNum); _variant_t var; CString str,strnum; CString strSendFW,strSendFY,strSendQX; CString strSend; str=""; SQLNum++; if(SQLNum==130) SQLNum-=129; strSql.Format("%d",SQLNum); strnum=strSql; strSql.Format("SELECT * FROM TB_FANGWEI WHERE ID = '%s'",strnum); try { //先关闭已经打开的记录集对象 m_pRecordset->Close(); //根据新的Sql查询语句，重新打开记录集对象 m_pRecordset->Open(strSql.AllocSysString(), theApp.m_pConnection.GetInterfacePtr(), adOpenDynamic, adLockOptimistic, adCmdText); } catch(_com_error *e) { AfxMessageBox(e->ErrorMessage()); } //在ADO操作中建议语句中要常用try...catch()来捕获错误信息， //因为它有时会经常出现一些想不到的错误。 var = m_pRecordset->GetCollect("Value"); if(var.vt != VT_NULL) str = (LPCSTR)_bstr_t(var); m_strAGFW=str; var = m_pRecordset->GetCollect("HexValue"); if(var.vt != VT_NULL) str = (LPCSTR)_bstr_t(var); strSendFW=str; // char* pszTest = (char*)(LPCTSTR)strSendFW; // unsigned char* ptr=(unsigned char*)pszTest; // unsigned char uchartemp; // unsigned char m=4; unsigned int intFW=(unsigned int)_tcstoul(strSendFW, 0, 16); intFW&=0x3fff; intFW<<=2; intFW|=0x0000; strSql.Format("SELECT * FROM TB_FUYANG WHERE ID = '%s'",strnum); try { //先关闭已经打开的记录集对象 m_pRecordset->Close(); //根据新的Sql查询语句，重新打开记录集对象 m_pRecordset->Open(strSql.AllocSysString(), theApp.m_pConnection.GetInterfacePtr(), adOpenDynamic, adLockOptimistic, adCmdText); } catch(_com_error *e) { AfxMessageBox(e->Err

void CSerialRecieveDlg::OnBtnAutosend() { // TODO: Add your control notification handler code here if(!m_ctrlMSCommCOM1.GetPortOpen()) AfxMessageBox("please open the port!"); else { CCreateName Dlg; CString TB_Name; CString mstr; if(Dlg.DoModal()==IDOK) { TB_Name=Dlg.m_TableName; } m_pRecordset->Close(); //// create a new table in SQL mstr.Format("IF NOT EXISTS (SELECT * FROM sysobjects WHERE name = '"); mstr+=TB_Name; mstr+="') CREATE TABLE "; mstr+=TB_Name; mstr+=" (ID INT,FangWei TEXT,FuYang TEXT,QingXie TEXT)"; try { m_pRecordset->Open(mstr.AllocSysString theApp.m_pConnection.GetInterfacePtr(), adOpenDynamic, adLockOptimistic, adCmdText); } catch(_com_error *e) { AfxMessageBox(e->ErrorMessage()); } SetTimer(1,500,NULL); } } when debug to the end, appear an error about "stackoverflow" what is the problem??

wuhuaiji

void CSerialRecieveDlg::OnBtnAutosend() { // TODO: Add your control notification handler code here if(!m_ctrlMSCommCOM1.GetPortOpen()) AfxMessageBox("please open the port!"); else { CCreateName Dlg; CString TB_Name; CString mstr; if(Dlg.DoModal()==IDOK) { TB_Name=Dlg.m_TableName; } m_pRecordset->Close(); //// create a new table in SQL mstr.Format("IF NOT EXISTS (SELECT * FROM sysobjects WHERE name = '"); mstr+=TB_Name; mstr+="') CREATE TABLE "; mstr+=TB_Name; mstr+=" (ID INT,FangWei TEXT,FuYang TEXT,QingXie TEXT)"; try { m_pRecordset->Open(mstr.AllocSysString theApp.m_pConnection.GetInterfacePtr(), adOpenDynamic, adLockOptimistic, adCmdText); } catch(_com_error *e) { AfxMessageBox(e->ErrorMessage()); } SetTimer(1,500,NULL); } } when dibug to the end, appear an ERROR about "stackoverflow" what is the problem??

wuhuaiji

firstly thanks again, by the way,i am so sorry, that i do not really understand what you write above, and i do not know in VC++ , how to create a table, just like the question i write "a problem about m_pConnection->Execute", have you a good way to resolve it, or can can you tell me which problem exist in my program

wuhuaiji

str+="CREATE TABLE "; str+=m_TableName; str+="(ID INTEGER,FangWei TEXT,FuYang TEXT,QingXie TEXT)"; try{ m_pConnection->Execute(str.AllocSysString(),&RecordsAffected,adCmdText); } when debug to here, the following appear: Unhandled exception in SerialRecieve.exe(KERNEL32.DLL):0xE06D7363:Microsoft C++ Exception. str is a CString variable,which is the table name, the program passed the compile and the build, but when debug, it can not go through. maybe it is a easy problem, but i can not resolve it help me please! thanks a lot!

wuhuaiji