Hi! I'm starting to write an application (c++, mfc of course ;)) that has the primary task to show data from a database. Actually it isn't my first application written in c++ that access to a database to read data but probably it will be the most complex. For this reason I was wondering if you have some advice about the design of this kind of applications... On top of my worries there is how to manage queries: I'm sure that in the future there will be a lot of changes so, probably, my usual way (simply build a class "around" the structure of recordset's query) to manage this things could be limited. So my question: there is something similar to the data abastraction layer that .net provides but for unmanaged code? There are some rules/advices that I should know? Any links to turorials, books and so on it will be really apreciated :) Regards, Francesco P.S. I'm sorry if this post isn't exactly on topic with the forum. If you think that another forum could be a better choice let me know and I will move the question there.

TBEditor: a pandapowered app!

Here and here a few more too ;) TBEditor: a pandapowered app!

krmed wrote:

As for the number of digits after, I don't have any quick ideas on that, but as you say, you could convert to a string (although you might get different results because of the precision of doubles) and then find the decimal.

int iNumAfter = 0; iNumAfter = 1 + (int)(log10(x*10)); Could it works? F. TBEditor: a pandapowered app!

Cedric Moonen wrote:

For the number of digits after the floating point, I don't have any idea.

well you can do the same... just multiply the initial number by 10 ... F. TBEditor: a pandapowered app!

Yup.. but with c# express you can get some icons and images: it's one of the bonus given with express editions and it's one of the main reasons because i downloaded c# express edition ;) By the way Here there are some links to icons' packages that I found around (maybe some of them in post read here :D). Francesco TBEditor: a pandapowered app!

Michael Martin wrote:

We have no access to any of the new series on DVD. Being Region 4 and all we are like the 3rd world.

This is the reason because I bought a region-free player... Well, it was sold as region 2 (Italy), but it was enought a simple cheat (something like up down return up up.. ;)) with remote control to change it to a region free player :) A region free player is a must: there are too many nice DVD in US that will never been imported here (e.g. Firefly is a great sci-fi serie too..) Francesco TBEditor: a pandapowered app!

Do you know the 2003 remake? It's great! :) I'm waiting the 11th of this month for the second part of the second season ;) Francesco TBEditor: a pandapowered app!

David O`Neil wrote:

You can get the Express Edition for free, just in case you hadn't heard. But you are probably looking for some of the advanced functionality...

I'm using it just to try new IDE and new MSDN... ;) Well.. I starded to develop with asp .net because I found visual web developer really nice :) Pity is that C++ express edition doesn't come with MFC: this mean that I must buy visual studio standard or professional.. but just for "playing" with C# or asp .net is a nice choice... Francesco TBEditor: a pandapowered app!

Ray Cassick wrote:

Its odd because I HATE the XP feature that groups like apps together.

yup.. the group button feature is the first thing that I disable on every "format c:" of my desktop :) After that I enable details listing and "show hidden files" in explorer and classic view in control panel :D TBEditor: a pandapowered app!

David Stone wrote:

Does anybody else find it kind of sad that they need an entire whitepaper to spell out the licensing for this stuff?

well is really sad.. :( At MS are missing one simple point: a clear list of differences beetween all their products' licenses. I don't need any enterprise, team or big visual studio edition. I simply bought V.Studio 5.0 educational and then VC++ std 6.0 and VC++ 2003 std... Every time was a pain find what I can do with my copy (can I write commercial application? can I upgrade to visual studio? can I....) My last question was: "Can I replace my standard edition with the new Express edition? (for commercial purpose for example..)" Well I found a partial answer only on forums... You can find a lot of lists about all items included in all VS editions but there isn't anything about licensing, commercial use or redistributable parts... The only way is read all EULA and tring to find an answer or go around microsoft site (that is huge!!) for hours... Maybe in MS thinks that a simple table is too complicated to write... TBEditor: a pandapowered app!

There are several example in codeproject using blowfish this and this are two implementation ;) Bye, Francesco

Hi, there are several libraries that can be used. Most of them supports a lot of algorithms. The most used should be Crypto++ but I'd like cryptlib also (in my opinion it's easier to use and to add in VC projects ;)). Imho it's really hard to understand how encryption works starting from code, so I suggest you to start from some RFC or something similar (a good example would be rjindael but you can "google" for a lot of other example ;)) Bye, Francesco

cedric moonen wrote: But this will crash after when you try to read the string in VB. Oh.. I missed that! Well.. I'm not using visual basic but I wrote some dll used by Delphi programs. We solved the same iusse using simple types like arrays of int/char instead of complex types like BSTR or pascal's string. I suppose that you can pass to dll_func a Byte array and then convert it to a string. Something like: Dim ByteArrayString(50) As Byte Here you can find something about bytearray to string conversion in Visual Basic. Hope this help. Bye, Francesco

Rick York wrote: Your idea was right as was your comment but your implementation does not use the max_size parameter. 'couse I'm lazy! :) I thought that I solved that problem with my " //use max_size to prevent buffer overflow" ;) Rick York wrote: Shouldn't that be : strncpy( str, "hallo world", max_size ); ? yes.. this should a good implementation. Personally I usually use something like: int dll_func(char* str,int max_size) { //use max_size to prevent buffer overflow ok.. I'm writing it :) const char dll_str[] = "hallo world!"; //assume that this is a variable caming from somewhere in the dll strncpy(str,"hallo world!",max_size); return strlen(dll_str); } so in main process you can check (if (dll_func(str,strsize) > strsize) ) if you have truncated the string and the real/needed size. Bye, Francesco :)

If I understand your problem, you should allocate a string in the main process and pass his pointer to the dll function. In the dll function you can copy the string and then return to main process. // somewhere in the main process { char* str; str = new char[50]; dll_func(str,50); // use str and clear memory ;) } // somewhere in dll void dll_func(char* str, int max_size) { //use max_size to prevent buffer overflow strcpy(str,"hallo world!"); return; }

Give a try to Bochs also... (it's free... but a little harder to use ;)) http://bochs.sourceforge.net/