How to get distinct list of a column from a DataTable

[Yi Jiang]

Hi;

I am trying to do some calc for a DataTable populated from database. The
DataTable has composite key e.g.ID, Date.

My question is:

What is the best and effective way to get the distinct list of ID
from DataTable just like SQL "select distinct ID from table"?


Thank you for your help!

Yi

 

[Val Mazur]

Hi,

If you need to get just a list of unique IDs, then what you could do is to
create DataView sorted using ID and then loop through the records to compare
previous and current value for ID. It will work pretty fast. If you need to
get a DataTable with distinct records, then you could use a helper class as
described in next KB

http://support.microsoft.com/default.aspx?scid=kb;en-us;325684&Product=adonet

 

[Yi Jiang]

Thank you very much!

Hi,

If you need to get just a list of unique IDs, then what you could do is to
create DataView sorted using ID and then loop through the records to compare
previous and current value for ID. It will work pretty fast. If you need to
get a DataTable with distinct records, then you could use a helper class as
described in next KB

http://support.microsoft.com/default.aspx?scid=kb;en-us;325684&Product=adonet