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From: Joseph M. Newcomer on 7 Jan 2009 23:09 All SQL documentation that specifies LPSTR/LPCSTR is erroneous. The header files for all the SQL APIs define -W versions that take LPWSTR/LPCWSTR parameters. In fact, in a couple cases the documentation erroneously specifes an LPSTR when the header says LPCSTR or an LPCSTR when the header says LPSTR. I have now added all of these to my Errors and Omissions document. joe On Wed, 7 Jan 2009 15:57:14 -0800, "Tom Serface" <tom(a)nospam.camaswood.com> wrote: >The help for SQLGetInstalledDrivers says: > >BOOL SQLGetInstalledDrivers( > LPSTR lpszBuf, > WORD cbBufMax, > WORD * pcbBufOut); > >Indicating that you have to use a char buffer, but it looks like it's >calling a W flavor which seems odd.... Even the error you're getting >doesn't make sense because the first You might try something like: > > TCHAR szBuf[2001]; > WORD cbBufMax = 2000 * sizeof(TCHAR); > WORD cbBufOut; > LPTSTR *pszBuf = szBuf; // Not sure what you're using this for exactly >maybe you intended to pass this into the function instead? > >This link might have something useful for you. I admit I haven't used this >function so I'm sort of just guessing here. > >http://bugs.mysql.com/bug.php?id=35776 > >Tom > > >"hamishd" <Hamish.Dean(a)gmail.com> wrote in message >news:dc1f26c5-6e3e-435a-9219-af0c908f09de(a)s9g2000prg.googlegroups.com... >> Hi - sorry this is my 3rd question recently. I'm having trouble with >> strings and characters and unicode in general; can anybody suggest a >> good article to read which explains the basics? >> >> My project is _UNICODE defined. However, a file I got from codeproject >> is not. Their code is below, but it cannot compile. >> >> char szBuf[2001]; >> WORD cbBufMax = 2000; >> WORD cbBufOut; >> char *pszBuf = szBuf; >> >> SQLGetInstalledDrivers(szBuf,cbBufMax,& cbBufOut); >> >> I would have thought changing the char's to TCHAR's would fix.. >> however, I still get "error C2664: 'SQLGetInstalledDriversW' : cannot >> convert parameter 1 from 'char [2001]' to 'unsigned short *'" >> >> Incidentally, I am trying to read data from an excel spreadsheet, and >> trying the CSpreadSheet class from >> http://www.codeproject.com/KB/database/cspreadsheet.aspx. Joseph M. Newcomer [MVP] email: newcomer(a)flounder.com Web: http://www.flounder.com MVP Tips: http://www.flounder.com/mvp_tips.htm
From: Mihai N. on 8 Jan 2009 00:05 > My project is _UNICODE defined. However, a file I got from codeproject > is not. You must always define both UNICODE and _UNICODE. UNICODE controls the Win API, _UNICODE controls the CRT API. To move something to Unicode you can also give a try to this: http://www.mihai-nita.net/article.php?artID=tounicode -- Mihai Nita [Microsoft MVP, Visual C++] http://www.mihai-nita.net ------------------------------------------ Replace _year_ with _ to get the real email
From: Mihai N. on 8 Jan 2009 00:11 > TCHAR szBuf[2001]; > WORD cbBufMax = 2000 * sizeof(TCHAR); Cleaner code trick: TCHAR szBuf[2001]; WORD cbBufMax = _countof(szBuf) - 1; This way you don't care about sizeof(TCHAR) and you don't deal with magic numbers in many places. _countof is a template thing available in newer VS versions. If there is any chance that the code will need to be compiled on VS 6, I usually do something like this: #ifndef _countof #define _countof(array) (sizeof(array)/sizeof(array[0])) #endif The nice part about the template version is that it complains if applied on a pointer. -- Mihai Nita [Microsoft MVP, Visual C++] http://www.mihai-nita.net ------------------------------------------ Replace _year_ with _ to get the real email
From: David Ching on 8 Jan 2009 00:58 "Mihai N." <nmihai_year_2000(a)yahoo.com> wrote in message news:Xns9B8CD781BB774MihaiN(a)207.46.248.16... >> TCHAR szBuf[2001]; >> WORD cbBufMax = 2000 * sizeof(TCHAR); > > Cleaner code trick: > TCHAR szBuf[2001]; > WORD cbBufMax = _countof(szBuf) - 1; > > This way you don't care about sizeof(TCHAR) and you don't deal > with magic numbers in many places. > > > _countof is a template thing available in newer VS versions. > If there is any chance that the code will need to be compiled > on VS 6, I usually do something like this: > > #ifndef _countof > #define _countof(array) (sizeof(array)/sizeof(array[0])) > #endif > > The nice part about the template version is that it complains if > applied on a pointer. > OK I'm confused: WORD cbBufMax = 2000 * sizeof(TCHAR); // <-- in UNICODE, this is 4000 but TCHAR szBuf[2001]; WORD cbBufMax = _countof(szBuf) - 1; // <-- in UNICODE, this is 2000 So these are not equivalent in UNICODE (but they are in non-UNICODE). Thanks, David
From: Tom Serface on 8 Jan 2009 02:28
I believe countof gives you the size of the array regardless of the size of the items in the array whereas sizeof gives you the sizeof the item. I think in the case of OP's function it wants the length of the buffer in bytes rather than chars. That's why I used sizeof in this case. Tom "David Ching" <dc(a)remove-this.dcsoft.com> wrote in message news:A6C7B9A3-DC41-432F-8463-600F5E487D6F(a)microsoft.com... > > "Mihai N." <nmihai_year_2000(a)yahoo.com> wrote in message > news:Xns9B8CD781BB774MihaiN(a)207.46.248.16... > OK I'm confused: > > WORD cbBufMax = 2000 * sizeof(TCHAR); // <-- in UNICODE, this is > 4000 > > but > > TCHAR szBuf[2001]; > WORD cbBufMax = _countof(szBuf) - 1; // <-- in UNICODE, this is > 2000 > > > So these are not equivalent in UNICODE (but they are in non-UNICODE). > > > Thanks, > David |