If you have it in memory, you won't get changings. And if you add code to support changings during runtime, you may not need a database. Assuming that all modules must then use only one function to access the memory db, why not implement the only function using direct db access? In both cases, that function must be thread safe using locking. I think that's your problem: You access the db from different threads which may fail when the db is locked by another thread. You will have similar problems when using a memory image that is modified when not using locking (but without getting an error message).

Hi Selva, SelvaKr wrote: Tool tips are specified in the resource as direct strings in the prompt field of the properties. The VC resource editor intends to help you to create toolbar tooltips, they are actually in the resource stringtable. For instance in your .rc file you have: STRINGTABLE BEGIN ID_FILE_NEW "Create a new document\nNew" A toolbar button's tooltip is the part of the string resource with same ID following '\n'. As the part preceding '\n' is the status bar text when a menu entry with same ID is hovered you can localize the strings matching your menus and toolbars in one step. cheers, AR When the wise (person) points at the moon the fool looks at the finger (Chinese proverb)

Thanks Johnny... Selva

Hi Ash, Thanks. It works. Selva

Thanks cmk. Selva

Hi Luc, Thanks for you reply. But my problem was a little different. I had a few thread local variable declarations in the MFC DLL which caused problem while loading at runtime. Now working on it to change the implementation of the variable. Thanks again. Selva

thanks for assistance

Perhaps your problem is using the MainWnd object across threads (you didn't say if this is MFC or not, but I suspect it is). It would be safer to either pass the hWnd of your main window in the thread parameters when you start the thread, or to use GetSafeHwnd() when you send your message. For example: Worker thread { get status from DB. ::SendMessage(GetMainWnd()->GetSafeHwnd(),PROC_MSG, wp, g_nInt) ..... ::SendMessage(GetMainWnd()->GetSafeHwnd(),PROC_MSG, wp, g_nInt) ......... } Also, you say the code will "look like" below. Post your actual code, including how you start the thread. Hope that helps. Karl - WK5M PP-ASEL-IA (N43CS) PGP Key: 0xDB02E193 PGP Key Fingerprint: 8F06 5A2E 2735 892B 821C 871A 0411 94EA DB02 E193

First of all, let me salute your patience. 2 days? Not bad. You don't need an explicit close() since it's taken care of in the destructor if it's still open. (Of course, you need to delete the CDatabase object if it's allocated in the heap.) Try without, and see what happens. You should be able to call close() multiple times, so there is probably something fishy in you code (or ODBC driver). home

SelvaKr wrote: But Access supports shared access of DB. isn't it? As far as I know it does. But you first need to determine what process has the file(s) open such that machine B cannot update them. Is it your application running on machine A, or some other application? "Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman "To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

SelvaKr wrote: after the next restart the entire file has only 0's. it is getting corrupted. I sense that you are after a way of writing mission critical data in an guaranteed safe way, so that integrity is maintained, even during a powerfailure halfway tru the write. I have done quite a bit of research on this,and came to the following design conclusions.- 1. It is Not possible to guarantee a successfull write under above circumstances 2. It is possible as Second Best, to maintain a consistent state. This means that under such circumstances, the transaction is either completed in full, or you are returned to the state prevailing before the transaction commenced. This is not a guaranteed write, but, atleast, you have not the corruption of a partially completed transaction. My system requires two identical file sets, marked Primary and Alternate. There is also a single third file, the State file, which holds only One Byte. This Byte assumes one of the following Values:- STATE_NORMAL, STATE_MOD_PRIMARY, STATE_MOD_ALTERNATE. When we start, Both Primary ad Alternate Sets are Identical. Step 1: The Write Operation commences by opening the State File, and Writing STATE_MOD_PRIMARY to it, after which it is closed. This indicates that the Primary Set is now entering into a potentially unstable State, but the Alternate holds a consistent backup. Step 2: Carry Out All your Writes to the Primary Set. When the Write is Completed, Close All Files. Step 3: Open the State File, and Write STATE_MOD_ALTERNATE to it, after which it is closed. This indicates that the Alternate Set is now entering into a potentially unstable State, but the Primary Set holds the New Dataset. Step 4: Delete All Alternate Files, and replace them with copies of the Primary Set. Step 5: Open the State File, and Write STATE_MOD_NORMAL to it, after which it is closed. This indicates that the Data Set is Once again in a Stable state. When your Excecutable starts, it must investigate the FileTime's of the State File, the Primary Set, and the Alternate Set. A Prima Facia Consistent state is indicated by FileTime(Primary) Another Consistency test is that the State File contains STATE_MOD_NORMAL If any of this fails, you can figure out from the above description, where things

SelvaKr wrote: But i want it to get added at the middle. Is there any way to achieve this. If it was me I would start by questioning the requirement, because it suggests that someone either doesn't know how databases work and/or are using it incorrectly for some other purpose. But excluding that you would have to 1. Create temporary table. 2. Copy all of the data to the temp table. 3. Delete the original table. 4. Re-create with the new column 5. Copy all of the data back to the newly created table. 6. Delete the temp table. Obviously you will need to deal with foreign keys appropriately. And it is likely that that the database can not be active (not processing work) while this is going on.

http://msdn2.microsoft.com/en-us/library/ms997649.aspx[^] --Mike-- Visual C++ MVP :cool: LINKS~! Ericahist | PimpFish | CP SearchBar v3.0 | C++ Forum FAQ Hungarian notation FTW

Not without seeing your code and, even then, I probably can't provide too much help since this is something I haven't done. Also, your problem is probably in the driver and drivers are not within the purview of this site. Try a driver development site. If you do go to a driver site, be warned: Providing unfettered user access to kernel memory is highly frowned upon since it is a huge security hole and invites BSODs. There is almost always a better safer way and one of the first responses you will get will be "why this way instead of the proper way". Judy

Can't you do that by settings pointers to memory locations you want to read and print them out to console?

Thanks a lot Randor. I have already referred the link and i am proceeding in the same way. Actually my physical memory reading works for some other address but not to the addresses that are device driver oriented. I have just calculated the cdrom.sys driver's load address and tried to read the same from the kernel memory. But it simple shows "FF" in all bytes :-( Any thoughts.... Selva

Thanks David. But it shows 518MB now..But the actual memory is only 512 MB. What could be the problem.. Thanks Selva

Dialog based application in system account?? Got my 1. Never display or use windows in a desktop you can't control. At least so I understood the notions of HWINSTA and HDESK. Nuclear launch detected