DataTable Sorting Positive and Negative values

Question

0.00/5 (No votes)

See more:

I have a Datatable dt

The values in the DataTable are both +ve and -ve.
I need to sort the values from smallest to Largest

When I sort in ASC order the least value is at the bottom
I have to traverse all columns to sort the DataTable
How can I sort the Table
_____________________________________
New1 | New2 | New3 |
____________________________________|
-0.1646 | 1.21 | 1.311
-0.1431 | 1.25 | -1.313
-0.1445 | 1.31 | 1.314
-0.1259 | 1.32 | -1.312
-0.1274 | 1.37 | 1.313
-0.1507 | 1.39 | -1.315

C#

private static DataTable CompareTwoDataTable(DataTable table1, DataTable table2)
{
    DataTable table3 = new DataTable();
    DataRow dr = null;
    string filterExp = string.Empty;
    for (int i = 0; i < table1.Rows.Count; i++)
    {

        string col = table1.Rows[i]["Par Name"].ToString();
        if (table2.Columns.Contains(col))
        {
            if (!table3.Columns.Contains(col))
            {
                table3.Columns.Add(col, typeof(string));
                filterExp = filterExp + col + " asc ,";
            }

            for (int j = 0; j < table2.Rows.Count; j++)
            {
                if (table3.Rows.Count != table2.Rows.Count)
                {
                    dr = table3.NewRow();
                    table3.Rows.Add(dr);
                }
                table3.Rows[j][col] = (table2.Rows[j][col]).ToString()
            }


        }

    }
    DataView dv = new DataView(table3);
    filterExp = filterExp.TrimEnd(',');
    dv.Sort = filterExp;
    table3 = dv.ToTable();

    return table3;
}

Posted 4-Mar-14 5:44am

FarhanShariff

Updated 5-Mar-14 1:59am

v6

Add a Solution

Comments

Richard MacCutchan 4-Mar-14 11:49am

That looks like it has been sorted on NEW2, not NEW1.

FarhanShariff 5-Mar-14 6:03am

The table3 was built by comparing two other table1 and table2.
I want to sort table3 from smallest to largest
Negative values it is not considering negative sign when looking for smallest Value.In case of Negative Values larger the value smaller is the number

FarhanShariff 5-Mar-14 6:06am

private static DataTable CompareTwoDataTable(DataTable table1, DataTable table2)
{
DataTable table3 = new DataTable();
DataRow dr = null;
string filterExp = string.Empty;
for (int i = 0; i < table1.Rows.Count; i++)
{

string col = table1.Rows[i]["Par Name"].ToString();
if (table2.Columns.Contains(col))
{
if (!table3.Columns.Contains(col))
{
table3.Columns.Add(col, typeof(decimal));
filterExp = filterExp + col + " asc ,";
}

for (int j = 0; j < table2.Rows.Count; j++)
{
if (table3.Rows.Count != table2.Rows.Count)
{
dr = table3.NewRow();
table3.Rows.Add(dr);
}
table3.Rows[j][col] = Convert.ToDecimal((table2.Rows[j][col]).ToString());
}

}

}
DataView dv = new DataView(table3);
filterExp = filterExp.TrimEnd(',');
dv.Sort = filterExp;
table3 = dv.ToTable();

return table3;
}

Amalraj Ramesh 4-Mar-14 11:52am

you already done it..

DataView dv = table2.DefaultView;
dv.Sort = "NEW1 ASC";
DataTable sortedDT = dv.ToTable();

What is the problem here..?

FarhanShariff 5-Mar-14 4:17am

The table has negative values it is not considering negative sign when looking for smallest Value

Richard MacCutchan 5-Mar-14 7:01am

Why are you tryng to convert real numbers to decimal? Use proper signed float values and your sort should work.

FarhanShariff 5-Mar-14 7:37am

How to change it . when i try to change it says Expected type is Decimal.

Richard MacCutchan 5-Mar-14 7:45am

Then store a Decimal, not a String. You need to be consistent with your use of types.

Richard MacCutchan 5-Mar-14 7:49am

Please do not keep posting code blocks in the comments section. Edit your original question, add the latest code (within <pre> tags as I have done), and provide exact details of what is happening.

FarhanShariff 5-Mar-14 7:51am

ok wait let me edit it

FarhanShariff 5-Mar-14 8:31am

please check this post you will understand better http://www.codeproject.com/Questions/739262/Compare-tables-and-sort-the-rd-table

FarhanShariff 5-Mar-14 8:01am

I have changed decimal to string and removed contertodecimal... now -ve sign is not considered and instead of smallest to largest it is other way round

Member 4330673 13-Jun-15 11:04am

I have a similar issue with the datatable

System.Data.DataView view = new System.Data.DataView(yourOriginalTable);
System.Data.DataTable selected =
view.ToTable("Selected", false, "SKU", "AttributeName", "Value");

DataTable dtCloned = selected.Clone();
dtCloned.Columns[2].DataType = Type.GetType("System.Decimal");
foreach (DataRow row in selected.Rows)
{
dtCloned.ImportRow(row);
}
dtCloned.DefaultView.Sort = "Value ASC";

But Value column is not sorting, 10.0 value should go to the bottom while its showing
on top that's the issue. help me to sort it out

Value Column having values:
10.0
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Maciej Los · Answer 1 · 2014-03-04T05:53:00

Solution 1

Have a look here: Filtering and Sorting Directly in Data Tables[^]

Posted 4-Mar-14 5:53am

Maciej Los

Comments

Sergey Alexandrovich Kryukov 4-Mar-14 17:26pm

5ed.
—SA

Maciej Los 4-Mar-14 17:27pm

Thank you, Sergey ;)

FarhanShariff 5-Mar-14 3:47am

The table has negative values it is not considering negative sign when looking for smallest Value.In case of Negative Values larger the value smaller is the number