DataTableReader is invalid for current DataTable 'TempTable' [closed]

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I'm getting the following error whenever my code creates a DataTableReader from a valid DataTable Object:

"DataTableReader is invalid for current DataTable 'TempTable'."

The thing is, if I reboot my machine, it works fine for an undetermined amount of time, then dies with the above. The code that throws this error could have been working fine for hours and then: bang. you get this error. It's not limited to one line either; it's every single location that a DataTableReader is used. Also, this error does NOT occur on the production web server - ever.

This has been driving me nuts for the best part of a week, and I've failed to find anything on Google that could help 开发者_运维问答(as I'm pretty positive this isn't a coding issue).

Some technical info:

DEV Box: Vista 32bit (with all current windows updates) Visual Studio 2008 v9.0.30729.1 SP dotNet Framework 3.5 SP1

SQL Server: Microsoft SQL Server 2005 Standard Edition- 9.00.4035.00 (X64) Windows 2003 64bit (with all current windows updates)

Web Server: Windows 2003 64bit (with all current windows updates)

Any help, ideas, or advice would be greatly appreciated!

UPDATE 1:

Ok - Have tried the following now with no success:

1: Rebooted 2: SFC / ScanNow 3: Changed SQL Servers 4: Tried a different method that uses DataTableReaders 5: Cleaned solution

The only thing I did find that worked was copy & pasting the code from the main Visual studio instance, into another which had a simple console app. This then worked as expected (queried database and got results into a dataTable, created a datatablereader on that table, then queried hasrows before calling .Read()... All of which worked.

I am struggling to see what could cause this, as there are NO code faults - i'm 100% certain, as it runs perfectly when published to the webserver.

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I think using the while(reader.read()) may solve your problem.

if (myReader.HasRows)
   while (myReader.Read())
     Console.WriteLine("\t{0}\t{1}", myReader.GetInt32(0), myReader.GetString(1));
else
   Console.WriteLine("No rows returned.");
myReader.Close();

UPDATE: Also from msdn: The HasRows property returns information about the current result set. If the DataTableReader contains multiple result sets, you can examine the value of the HasRows property immediately after you call the NextResult method in order to determine whether the new result set contains rows.

Use the HasRows property to avoid the requirement to call the Read method of the DataTableReader if there are no rows within the current result set.

DataTableReader.HasRows Property

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Had the same problem and got rid of it after clearing the variables in the watch window.

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Clearing the watch window & doing rebuilds worked for me. However, because I had to remember to frequently rebuild, I eventually just renamed it also. (prior to renaming, adding additional watch variables on an object could cause previous watch variables on that object to become invalid -- even without progressing through the code, ie staying on the same line)

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Wrap usage of DataTableReader (and all IDisposables) with using.

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OK.. Further down in the code, I have the following code:

using (DataTableReader tr = dtCustomers.CreateDataReader())
{
    ....
}

If I change this to read:

using (DataTableReader tr2 = dtCustomers.CreateDataReader())
{
    ....
}

Then, and remember this bit of code is much later down in the same procedure, BOTH bits of code work without fault!

So, this doesn't work:

using (DataTableReader tr = dt.CreateDataReader())
{
    ...
}

....

using (DataTableReader tr = dt.CreateDataReader())
{
    ...
}

But this does:

using (DataTableReader tr = dt.CreateDataReader())
{
    ...
}

....

using (DataTableReader tr2 = dt.CreateDataReader())
{
    ...
}

I don't understand why this way works, but it does and as I've not had another answer, I'll be going with this.

If you know why this works, and why the original doesn't, please can you enlighten me? :)

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Just thought I would post on here in case it's helps someone else. I tried a number of things and in the end i simply changed the name of the datareader and it worked, kind of similar to here. i dont know why for sure but i think it might be because the datareader (originally) wasnt being closed, so maybe after a few times debugging, there was lots of "stuff" in memory with a certain name attached and it said "no more!". still, i could be talking bullpies. my advice, change the name of your datareader variable and make sure you close it after you use it

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Seems like a bug on getting the tableReader... i have code that has been working for ears and if i change another method sometimes i get that errro... some times it's solved just recompiling (rebuild), another times i reinstalled the .NET framework or use the option repair of it... i am starting to put try catch sections to use the reader if the system "wants" to givme the reader and the DataTable if not. Greetings.