How to Avoid Duplicate Rows In DataTable
Problem
One of the common problems faced in the data retrieval is to avoid duplicate rows from dataset or datatable. If you google for it, you will come across many solutions asking to loop through the complete in order to get rid of the duplicates. There is a very simple solution available in .Net that does not need looping but it comes with one problem that it can apply duplicate on a single column only.
Solution
For a dataset the following line will return distinct records for the column:
ds.Tables["MyTable"].DefaultView.ToTable(true,”column_name”);
For a datatable the following line of code will return distince records for the column:
dt.DefaultView.ToTable( true, “column_name”);
The first parameter of ToTable is a boolean for distinct or non-distinct. The second one is the name of the column. It is as simple as it looks 
Hi, interesting post. I have been wondering about this issue,so thanks for posting. I’ll likely be subscribing to your site. Keep up great writing
But the problem with this is that it only returns one column for example.
if you have a table with column
employee_name, employee_address, employee_department
and data
——————————————————-
Waseem abc, lahore IT
Waseem abc, Islamabad Finance
and you want to get the complete distinct row based on employee name then it will only return employee name in result not the complete row.
Is there a way to apply distinct filter on dataset or datatable so that we can get complete distinct row
Yeah qasim, that’s why I have mentioned the limitation as well so that reader knows the limitation before proceeding further on the solution.
You can use more than one column too in second parameter like,
ds.Tables["MyTable"].DefaultView.ToTable(true,”column_name1”,”column_name2”);
So that u can get the distinct rows with many columns.