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It's spelled 'database' ( just in case you were trying to google your problem ).
What sort of DB is it, Access ? And it's a local file ? If you're seeing the wrong one, then your app is pointing to the wrong one, simple as that.
Christian Graus - Microsoft MVP - C++
"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )
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its access db and the connection is ok their are no error
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Well, it's quite obvious you're connecting to a different DB than the one you want to, so there is obviously an error in your connection string. Or you give a relative path and fail to consider where you're putting your DB and where you app ends up.
Christian Graus - Microsoft MVP - C++
"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )
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Public ConStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _<br />
"Data Source =" & Application.StartupPath & "\ITDSS.mdb"<br />
Public con As New OleDbConnection(ConStr)<br />
this is my connection it have to look at the debug file
please help because it have the same name
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Path.Combine is a wiser choice, but this code will work. In this case, I suspect you're not correct in your assumption of where the startup path is. This code will load the database in either the debug or release folder, depending on your config. It's not a relative path, if that file is not there, it will crash.
Christian Graus - Microsoft MVP - C++
"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )
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it work now i change the db in all the file in my project
thanks  
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I want to find some solution that can solve expression like this
(98.83*(a1^3))-(89127*a1)-53480000 = 0
a1 ^ 3 = cos(a1) / (279 ^ 2) - 0.30293
I want to know value of a1
- The expression have a1 variable.
- a1 can has more than one time in expression.
- a1 can in left side and right side.
I searched by uses keywords "expression solver" then I found many solutions but they aren't match
my requirements
many solution can find result of expression e.g 2 ^ 5 + (300 * 4)
by use stack,prefix,postfix
but I not found a solution that can find variable value.
if you have any solution even it isn't use vb.net please help me.
or may be you suggest me to use other keywords for search actually I don't know what a keyword i should use because my English skill isn't well.
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Hi,
seems to me you need two things:
1. some code that evaluates an expression such as
y = (98.83*(a1^3))-(89127*a1)-53480000
or y = a1 ^ 3 - cos(a1) / (279 ^ 2) + 0.30293
for a specific value of a1
2. some code that finds the zeroes of y(a1), i.e. those values of a1 for which
y effectively becomes zero.
You can do 1. the lazy way by editing it into a source file, i.e. make a specific
program. Or you need a parser + expression evaluator, which have been handled
in several CP articles.
You can do 2. using a simple algorithm, I would suggest "Newton-Raphson" which
basically says: for a given approximation x to the solution,
x - y(x)/y'(x) is a better approximation.
Here y' is the derivative, which you can obtain in two ways:
- you could come up with its analytical form and add it to the source code as suchl
or you could do it symbolically by writing a parser + derivative generator,
I don't recall having seen one on CP yet.
- and you could approximate y'(x) by calculating y(x) and y(x+dx) and
setting y'(x)=(y(x+dx)-y(x))/dx which may be a good enough approximation
for small dx.
Warning: if you come up with an arbitrary expression in a1, there could be
zero, one, two, or any number of solutions. Since iterative approaches need
an initial guess, they tend to converge (at best) to one or a few of the solutions,
there is no easy way to find all solutions.
Warning2: Newton-Raphson may not converge at all, if your initial guess is
far away from a real solution but close to a local minimum/maximum, it may just
move and stay there.
Warning3: you will need defensive programming to protect yourself against
overflow, underflow, zero divide, and non-convergence.
There are some web sites that solve simple equations for you, and even tell
you how they do it. I don't remember having seen solutions for trig equations.
quadratics[^]
Newton[^]
Luc Pattyn [Forum Guidelines] [My Articles]
This month's tips:
- before you ask a question here, search CodeProject, then Google;
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get;
- use PRE tags to preserve formatting when showing multi-line code snippets.
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Thank you for your reply.It can help me a lot.
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you're welcome.
Luc Pattyn [Forum Guidelines] [My Articles]
This month's tips:
- before you ask a question here, search CodeProject, then Google;
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get;
- use PRE tags to preserve formatting when showing multi-line code snippets.
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System results in NOT RESPONDING state.
I want to have an infinite loop till end button is pressed. Through looping, I want to monitor few files. I used if, for, do, while, until , but none of them resulted in a fruitful way. Can anyone plz help me how I can achieve such looping. Plz help with examples.
Thanks in advance.
My code can be viewed here: http://www.codeproject.com/script/Forums/View.aspx?fid=1646&msg=2467756[^]
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arp_059 wrote: I want to have an infinite loop till end button is pressed
Then the loop must go on a different thread. If you loop infinitely then your application will not know about the button press because it is too busy looping to handle events.
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doesn't application.doevents check if anything else has happened/being pressed etc. I've used it before to put an exit function in a loop from a stop button.
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The ANZAC wrote: doesn't application.doevents check if anything else has happened/being pressed etc. I've used it before to put an exit function in a loop from a stop button.
Yes, but you could end up in some terrible recursion problems if you are not careful. The recommended way is to use separate threads.
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yeh i'm in agreeance, it really depends on the scale of your application too.
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You can create a defacto infinite loop with the timer control. Just drag and drop it into your project and when you set the enable property to true it generates an event periodically. You can then write code in that event to check your file. When you want to stop checking then set the enable property to false.
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How about using Timer control? Not so professional but still it gets the job done.
- Stop thinking in terms of limitations and start thinking in terms of possibilities -
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Hiii..,,,
Keep "Application.doevents" in your infinite loop. then Try.
Thanks
Rajesh B
Rajesh B --> A Poor Workman Blames His Tools <--
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Unless you're REALLY careful about what you're doing, using "DoEvents" in a workaround like this is a dangerous thing to do, causing some very difficult bugs to work out.
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Hi ,
i took datetimepicker its format is dd-MMM-yyyy
Command.Parameters.Add("@DOB", SqlDbType.DateTime, 50).Value = Format(dtpCustDOB.Value, "YYYY-MM-DD")
i am getting "Failed to convert parameter value from a String to a DateTime
Kindly suggest.
i tried with cdate
Thanks.
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soniasan wrote: Command.Parameters.Add("@DOB", SqlDbType.DateTime, 50).Value = Format(dtpCustDOB.Value, "YYYY-MM-DD")
i am getting "Failed to convert parameter value from a String to a DateTime
The errors suggests that you pass a DateTime object. So, why are you converting the DateTime object the Date Time picker gave you in to a string first?
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it is necessary to create DSN for using crystal report.
without using DSN we can create a crystal report.
i want to generate a dynamic crystal report from visual basic 6.0 and backend used is oracle.
i tried it but giving error like 'server not yet been started'.
i don't know TSNname for oracle.
give me reply.
if possible then a code for generating dyanamic report. with backend oracle assume i don't create any report file. from the first step. i just install vb and oracle with user name "dtbs" password "dtbs".
please help me.
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You have 2 major problems.
1 You are using a development platform 6 years out of date (VB6) and therefore the support level will be low (and skills thankfully forgotten)
2 You are attempting to use Crystal Reports, note there is no forum for CR because it is a PITA.
How does you app get at the database?
I used to build CR based on stored procs and a connection string but you can also use datasets passed from your application. If you cannot talk to the database you have a serious problem.
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OK, so I have a very basic application for a client that, right now, simply connects to a device, K8055. The application references a DLL, k8055d.dll, which is in the root directory of the project.
On application start-up, the device is connected to using the OpenDevice() function in the DLL file, which is precessed in a separate thread. Appropriate information, for example, if the application is unable to connect, is reported back to the end user.
In short, the application is connecting everytime the device is attached to the computer, and when it is not, this is reported back to the user. But there is a problem: when closing the form (not exiting the application), the following error occurs:
Title: [AppName].vshost.exe - Application Error
The exception unknown software exception (0x0eedfade) occured in the appication at location 0x7c812a5b
A further message appears, citing runtime error 217 at 00009C34.
The project compiles without any errors or warnings, and due to this, am beginning to think it is due to the DLL file, k8055d.dll. I have no suggestion and to how to fix this, and would like some help!? Please ... ?
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Your best source of information on this is going to be whoever wrote that library. With the information you've given, there's really nothing telling us what could be wrong.
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