DataTable.Select() PRoblem

jonhbt

I created a method that makes use of the .Select() method so that to check in a datatable if the value is already in the data table. For 1/4 of the recordss its working but at certain point it prompts out the fllowing error Min (14) must be less than or equal to max (-1) in a Range object. I am getting the data from MS Access. I have changed the databases so that to check if it was only with one version but It still showed me the error. only the number 14 changed. I have checked the records of the ids that the program was stopping all and they are all good values. Can some one help on that please. it is very urgent. THAnks alot for your time and help.

Tom Deketelaere

jonhbt wrote:

it is very urgent

Of course it is, all questions here are urgent to the poster. But this is a free site so... (hint don't post that again) As to your problem can you provide the code that does the select (so your method) and some of the values where the code gives that error on?

jonhbt

Sry for that I didn't want to cause any problems the code that I am using is this DataTable dtAllEmps = new DataTable(); dtAllEmps = cetData.GetALLEmployessByDate(conString, sensors); foreach (DataRow dataRow in dtAllEmps.Rows) { if(dtCSV.Rows.Count == 0) { DataRow newRow = dtCSV.NewRow(); newRow["UserID"] = dataRow["USERID"]; newRow["Department"] = dataRow["DEPTNAME"]; newRow["Date"] = dataRow["CHECKTIME"]; newRow["Name"] = dataRow["NAME"]; newRow["CheckType"] = dataRow["CHECKTYPE"]; dtCSV.Rows.Add(newRow); } else { Console.WriteLine("User ID " + dataRow["USERID"].ToString()); if (dataRow["USERID"].ToString() != "") { string strExpr = "UserID = " + dataRow["USERID"].ToString(); Console.WriteLine("Expression " + strExpr); DataRow[] filteredRows = dtCSV.Select(strExpr); if (filteredRows.Count() == 1) { Console.WriteLine("Number of Rows " + filteredRows.Count().ToString()); DataRow csvRow = filteredRows[0]; DateTime csvDate = Convert.ToDateTime(csvRow["Date"]); DateTime tableDate = Convert.ToDateTime(dataRow["CHECKTIME"]); Console.WriteLine("csvDate" + csvRow["Date"].ToString()); Console.WriteLine("tableDate" + dataRow["CHECKTIME"].ToString()); if (csvDate < tableDate) { filteredRows[0]["Date"] = tableDate.ToString(); filteredRows[0]["CheckType"] = dataRow["CHECKTYPE"].ToString(); filteredRows[0]["Department"] = dataRow["DEPTNAME"].ToString(); }

jonhbt

I am writing the console calls so that to know what is the last value that the program is having. It is crashing in this part. The values when the program throws the exception differ. string strExpr = "UserID = " + dataRow["USERID"].ToString(); Console.WriteLine("Expression " + strExpr); DataRow[] filteredRows = dtCSV.Select(strExpr);

MumbleB

Can you put a Try Catch in there and post the error message from the catch? Put the whole block of code from the foreach in a try block and then a catch at the end. This should give you better idea of what the error is.

Excellence is doing ordinary things extraordinarily well.

Tom Deketelaere

Don't worry you didn't cause problems, was just a hint. Another hint: When posting code use the 'code block' tags, makes it easier to read the code. As to your problem. At what userid does the error occur? My guess would be that since you do a 'tostring' your userid is of the type string (varchar). If so your filter expression should be:

"UserID = '" + datarow["USERID"].ToString() + "'";

jonhbt

I have a try catch but, only error prompting is System.argument Exception{"Min (14) must be less than or equal to max (-1) in a Range object."}

jonhbt

thanks for the advices. Regarding to the problem the values are Numbers in the database. There wasn't only one value since i tried different values. One of them was 279 which was giving problems. the strange thing is that this process runs for most of the values but at a certain point in time it stops. that is why i am confused, since all the values that are being passed are numbers.

Tom Deketelaere

Is your userid column in the datatable numeric? If so remove the tostring (not needed here) If not try the code I gave (but I don't think that's the problem)

jonhbt wrote:

the strange thing is that this process runs for most of the values but at a certain point in time it stops

Does it always stop at the same value? or is random? Are you using multi - threading?

jonhbt

no im not useing multi threading. The value is the same only for the set of values chosen. WHen i change the set of values by a filter from the select command in the database, the value is different.

Tom Deketelaere

When you debug and stop at the select line try doing a 'quick watch' (right mouse click) Then run the select (dtscv.select("Userid=" + newrow["userid"]) ). Does that work? Is the value present or not? Can you post your declaration of the dtscv datatable? (specifically the column declarations )

jonhbt

This is my declaration of te DataTable

DataColumn Column1 = new DataColumn("Name");
DataColumn Column2 = new DataColumn("Department");
DataColumn Column3 = new DataColumn("Date");
DataColumn Column4 = new DataColumn("UserID");
DataColumn Column5 = new DataColumn("CheckType");

            dtCSV.Columns.Add(Column1);
            dtCSV.Columns.Add(Column2);
            dtCSV.Columns.Add(Column3);
            dtCSV.Columns.Add(Column4);
            dtCSV.Columns.Add(Column5);

Ill try what you suggested

Tom Deketelaere

try:

DataColumn Column4 = new DataColumn("UserID",typeof(int));

jonhbt

I think that solved the problem. I stil have to takle the performance issue, but THANKS alot for your help