Exception "DataTableReader is invalid for current DataTable"

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4.00/5 (1 vote)

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Hello everybody,
I have some code that was working until recently, but suddenly started throwing the exception "DataTableReader is invalid for current DataTable". The strange is that this happens only when debuging. Release configuration runs normally.
The code is:

public static DataTable Get3wStatusesToSend() {
	DataSet oDataSet = new DataSet();
	string sGatherSQL = "SELECT * FROM ... ";
	SqlCommand oCommand = new SqlCommand(sGatherSQL);
	oCommand.Connection = OpenConnection();
	
	SqlDataAdapter oAdapter = new SqlDataAdapter(oCommand);
	oAdapter.Fill(oDataSet);
	oCommand.Connection.Close();
	return oDataSet.Tables[0];
}

and somewhere else

DataTableReader oReader = Get3wStatusesToSend().CreateDataReader();
while(oReader.Read()) {

At this point the exception is thrown.
The table is not empty, have checked and it has rows.
Any suggestions please.

Thanks in advance!

Posted 2-Jun-11 4:49am

AFokas

Updated 6-Jun-11 23:14pm

Ramalinga Koushik

v2

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3 solutions

Solution 3

I have had a similar problem. I am still not sure how to solve it, but I found the cause. In my case the problem was caused by a NULL value in one of the fields that were returned. As a matter of fact, if any of the fields contained a NULL value I would get the error “DataTableReader is invalid for current DataTable 'DataSet”

Posted 30-Jun-11 22:17pm

RZLR

Comments

AFokas 5-Jul-11 3:43am

Hello and thanks for your reply. Unfortunately this does not apply to me. The dataset that's returned does not have NULL values in it.

mfgirruite 2-Sep-14 7:57am

Thanks a lot,I couldn't find cause but now that you stated yours I even managed to solve my problem

Solution 2

Thanks for you reply.

I think that the SqlConnection has nothing to do since I'm working with DataTable.
I'm creating the DataTableReader from DataTable because I have this function.

public Checkpoint LoadFromDataReader(IDataReader oReader) {
	nkChk = (int)oReader["nkChk"];
	sChkStatus = ((string)oReader["sChkStatus"]).ToLower();
	sChkStatus3w = ((string)oReader["sChkStatus3w"]).ToLower();
	sChkSerial = ((string)oReader["sChkSerial"]).Trim();
	
	.
	.
	.
	return this;
}

while(oReader.Read()) {
	Checkpoint oCheckpoint = new Checkpoint().LoadFromDataReader(oReader);
}

and that way I can call it with any reader (SqlDataReader, DataTableReader, ...)

So I did this to try your solution

public Checkpoint LoadFromDataRow(DataRow oRow) {
	nkChk = (int)oRow["nkChk"];
	sChkStatus = ((string)oRow["sChkStatus"]).ToLower();
	sChkStatus3w = ((string)oRow["sChkStatus3w"]).ToLower();
	sChkSerial = ((string)oRow["sChkSerial"]).Trim();
	.
	.
	.
	return this;
}

foreach(DataRow oRow in oTable.Rows) {
	Checkpoint oCheckpoint = new Checkpoint().LoadFromDataRow(oRow);
}

and it works, but it spoils the generality. Also it keeps bugging me that it crashes only when debugging and that it was working fine until recently.
I will not accept your answer as solution yet, in case someone explains why is this happening, but I'll rate it with 5.

Posted 6-Jun-11 23:11pm

AFokas

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Kim Togo · Accepted Answer · 2011-06-04T21:32:00

Solution 1

You are closing the SqlConnection in method Get3wStatusesToSend. Perhaps it has something to do with that?

Alternative would I do a foreach on the DataTable returned from Get3wStatusesToSend method.

C#

DataTable tbl = Get3wStatusesToSend();

foreach (DataRow row in tbl.Rows)
{
  // Do processing of each row.
  string name = (string)row["name"]; // Get name from row
}

Posted 4-Jun-11 21:32pm

Kim Togo

Comments

ambarishtv 5-Jun-11 4:32am

+5 :)

Kim Togo 5-Jun-11 5:06am

Thanks :-)