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may be ur application is built in VS 2003 which first require conversion to VS 2005.
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I tried to insert some value to a table, I received the following error
<br />
no value given for one or more required parameters<br />
Here is the code; the ID field is the primary key autoincremented, I don't know how to set it; I simply set it to 1
<br />
OleDbConnection dbConnection;<br />
<br />
dbConnection = new OleDbConnection();<br />
<br />
dbConnection.ConnectionString = "Provider = Microsoft.Jet.OLEDB.4.0; " +<br />
<br />
"Data Source = " + Application.StartupPath + "\\Data.mdb";<br />
<br />
<br />
<br />
string sqlstr = "INSERT INTO Datas(ID, FirstName, LastName , Function, Description, SDate, EDate, THour)" +<br />
<br />
"VALUES(1, John, Do, FunctionOne, DescriptionOne, 12-02-03, 12-02-06, 20)";
<br />
<br />
<br />
OleDbCommand cmd = new OleDbCommand(sqlstr, dbConnection);<br />
<br />
<br />
<br />
try<br />
<br />
{<br />
<br />
dbConnection.Open();
<br />
cmd.ExecuteNonQuery();<br />
<br />
dbConnection.Close();<br />
<br />
}<br />
<br />
catch (Exception ex)<br />
<br />
{<br />
<br />
MessageBox.Show(ex.Message, "Database Error");<br />
<br />
}<br />
<br />
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if ID column is identity field
you are not suppose to include the column in insert list and values list
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You have forgotten to put apostrophes around the string values.
---
b { font-weight: normal; }
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What do you mean by putting string? I assume you mean something like that 'FunctionOne', etc. I will try that this evening.
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There may be some other fields in the table which do not allow null values
or
John, Do, FunctionOne, DescriptionOne --- if these are variable then
may be values are null or empty string.
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how to write the query to select 10 record from database
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Depends where the 10 records are. SELECT TOP 10 will get the first ten records matching the criteria. If you want 10 records in teh middle or end then you have more work to do.
only two letters away from being an asset
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Select top 10 * from <tblname>
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ok how to get next 10 records from table ?how to write query to get it
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You need to retrive 20 records and ignore top 10 to get next 10 records
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or
Select top 10 * from agent where agentid not in (select top 10 agentid from agent)
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How to change the Border style of Listbox in ASP .net
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Type this in and once you press the . the intellisense should show you a list of border styles.
this.ListBox1.BorderStyle = BorderStyle.
www.DaytonaForums.com
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I have tryed this one But it will change
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I have tryed this one But it will not change
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primaryStyle.BorderStyle =BorderStyle.Dotted;
ListBox1.ApplyStyle(primaryStyle);
How about that?
_____________________________
www.DaytonaForums.com
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there is no property like Primarystyle
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Does the framework perform any non-garbage-collector operations that slow down applications at time scales similar to thsoe of garbage collections?
I ask because in my C# code, a certain operation has a measured average case time of a few microseconds, but once in a while one of these operations takes 5000 times longer than the average. This does not appear to be attributable to varying latency in the memory hierarchy or to variations in the code path followed during the operation. Also, I have verified that no garbage collections occur during these long operations by verifying that GC.CollectionCount did not change during the operation.
My timing measurements measure real time, so a factor of 5000 slowdown could easily be due to the operating system, but I thought I would ask here to see if there are any other operations going on in the framework too.
(I am working on a hash table implementation for a real time system; I am interested in the worst-case times for add, remove, and retrieve operations.)
By the way.. Is there a convenient way to time a block of code without using real time measurements such as with WIN32 API calls to QueryPerformanceCounter and the like? It would be especially nice if the data were accessible from within the program so that the program could report the data and compute auxiliary statistics, instead of having to rely on extra steps that are usually required when using a profiler.
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Exceptions can do that. I suggest you attach a profiler, and see what the code does in that bad case.
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The slow operations are rare, at most 1 in 10,000 operations, probably less frequent than that. How would I track this down with a profiler?
Given the nature of the code it does not seem likely that exceptions are being thrown in its midst. There are some calls to the base class library but these use things like List<t> and do not seem likely to involve exceptions.
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A s h wrote: I have verified that no garbage collections occur during these long operations
In this case, it could be linked to Windows memory management. I do not know if you
allocate large blocks of memory, or a lot of small blocks. When you ask for memory,
windows will try not to allocate it. If you actually use the memory, that will cause
a page fault and windows will either create a new page, or swap one from the disk
(depending on the situation).
If you want your system to be under tight constraints, you might have to (try to) manage the
memory yourself.
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The class does small to medium size allocations, generally 32-1000 bytes at a time. The class implementation does a bit of custom memory management in the sense that it maintains a pool of objects for one type of commonly used object.
The class runs completely in managed code and I am not willing to change that - this is a general-purpose library-style implementation of a data structure (with essentially the same interface as ystems.Collection.Generic.Dictionary) that is intended for use within managed or unmanaged programs. The test framework does use the WIN32 API to do timing measurements. That is the only part of the test framework that runs in unmanaged code.
The amount of time used during these slowdowns is on the order of .02 seconds. Sorry for not mentioning this explicitly in the original post. This amount of time seems orders of magnitude too large to be accounted for by page faults. What do you think?
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You should take a look at:
http://blogs.msdn.com/ricom/[^]
Also you could search for "GC mid-life crisis", that would give you pointers to
more details on how the Garbage collector works, and interactions with the OS.
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Thanks.
I think I know what the slowdown is due to - it is probably due to JITting. Now, if I knew how to force the compiler to JIT everything without having to do it in an ad-hoc way like running the benchmark twice..
-- modified at 17:34 Tuesday 5th December, 2006
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