Why DataTable.Select sorts the data by default

Question

I have a dataset with the following data

Name          Value    Percent
0-3 months    0        0
3-12 months   0        0
1-5 years     1234.12  28
5-10 years    13144.11 68
10-15 years   0        0
Over 15 years 1233.44  14
Other Income  2245.12  

when I try

foreach (DataRow dr in dsMaturity.Tables[0].Select("name not like 'Other%'"))
{
    TotalValue += double.Parse(dr["Value"].ToString());
}

Edit: Actually, similar to the above code. I am using the similar loop to add the data to display bucket which eventually writes to the chart.

foreach (DataRow dr in dsMaturity.Tables[0].Rows)
{
    //Add to the display bucket
}

I get the data sorted like:

0-3 months
10-15 years
1-5 years
3-12 months
5-10 years
Over 15 years

Why? How can I have the data unsorted? This is critical since I show the data in my chart object. Am I missing something here?

Answer 1

dataTable.Select(filterExpression) does not guarantee a sort order. As the documentation says, you should use one fo the other overloads to supply your sort order.

In our experiment, the result set was ordered by the filter column, but I would not trust later versions of .NET to behave the same way (as it's not documented that way).

Answer 2

I had this problem too, the answer is:

dataTable.AsEnumerable();

instead of

dataTable.Select();