selecting row of datatable by duplicated value of one column

diamond diamond

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

4 Replies

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Dhirendra Misra12y ago
Accepted 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());
}
}
}
}
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diamond diamond12y ago
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
0
Dhirendra Misra12y ago
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.
0
Khan Abrar Ahmed12y ago
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
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