selecting row of datatable by duplicated value of one column

Question

Hi

I have a datatable which has 3 column. for one value of first column has many different value and some of them duplicated value in the second column. I want split the rows that are same value in second column.

first            second           third

1                 5                    d
1                 5                     w
1                 8                     q
1                 5                    y
1                 8    h
2                  4                   p
1                 5                    l
2                  4                   e

I want category be as same below:
view1:
1         5       d
1         5       w
1         5       y
1         5 l

view2:
1 8 h
1 8 q

view3:
2 4 e
2 4 p

Please help me
I need urgently

Dhirendra Misra · Answer

Hello Diamond I think same code you can use to create text files as below and then use those files where you want: Write a method to encapsulate it all: --------------- int oldValue = -1; int currValue = -1; int viewCounter = 0; string fileName = string.Empty; //Sort the dataTable dt.DefaultView.Sort = dt.Columns[1].ColumnName +  DESC; //2nd column //Loop DataTable foreach (DataRow row in dt.Rows) // Loop over the rows. { currValue = convert.Int32(row[1]); // 2nd column if (currValue != oldValue) { viewCounter++; oldValue = currValue; fileName = @C:\Temp\ + View + viewCounter.ToString() + .txt; // Create a new file using (StreamWriter sw = File.CreateText(fileName)) { sw.WriteLine(row[0].ToString() +   + row[1].ToString() +   + row[2].ToString()); } } else { if (File.Exists(fileName)) { using (StreamWriter sw = new StreamWriter(fileName)) { sw.WriteLine(row[0].ToString() +   + row[1].ToString() +   + row[2].ToString()); } } } }

diamond diamond · Answer

Hello Dhirendra Thanks a lot. of course I want to save same as view in a text file because after this split I should use them in formul. Are you have any idea?? Thanks

Dhirendra Misra · Answer

Hello Diamond If it is DataTable of c# you need to first sort the table and then use foreach to loop each values and create views. Like pseudo code as below: int oldValue = -1; int currValue = -1; int viewCounter = 0; dt.DefaultView.Sort = dt.Columns[1].ColumnName +  DESC; //2nd column foreach (DataRow row in dt.Rows) // Loop over the rows. { currValue = convert.Int32(row[1]); if (currValue != oldValue) { viewCounter++; oldValue = currValue; Console.WriteLine(view + viewCounter.toString()); //Print columns : Like row[0] row[1] row[2] } else { //Print columns : Like row[0] row[1] row[2] } } Hope it will help you.

Khan Abrar Ahmed · Answer

HI if your are using sql then use. DECLARE @t AS TABLE ([FIRST] INT [second] INT [third] VARCHAR(4)) INSERT INTO @t VALUES (1  5 'd') (1  5  'w') (1  8  'q') (1  5 'y') (1  8 'h') (2  4 'p') (1  5 'l') (2  4 'e') SELECT * FROM @t AS t WHERE FIRST =1 AND second=5 SELECT * FROM @t AS t WHERE FIRST =1 AND second=8 SELECT * FROM @t AS t WHERE FIRST =2 AND second=4