How to get distinct field list from datatable?

Question

A datatable as follow:

devID kk vv

t1 11 22

t1 22 22

t2 11 66

t3 88 99

t3 33 33

....................................

I want get a list or datarow[] like below:

["t1","t2","t3"]

Answer 1

For the new situation, try a code like this:

. . .
var results = new DataTable( );
results.Columns.Add( "devID", typeof( string ) );
results.Columns.Add( "devName", typeof( string ) );

dt.Rows
    .Cast<DataRow>( )
    .Select( r => new { devID = r.Field<string>( "devID" ), devName = r.Field<string>( "devName" ) } )
    .Distinct( )
    .All( t => { results.Rows.Add( t.devID, t.devName ); return true; } );

Answer 2

Check an example:

var dt = new DataTable( );
dt.Columns.Add( "devID", typeof( string ) );
dt.Columns.Add( "kk", typeof( int ) );
dt.Columns.Add( "vv", typeof( int ) );

dt.Rows.Add( "t1", 11, 22 );
dt.Rows.Add( "t1", 11, 22 );
dt.Rows.Add( "t1", 22, 22 );
dt.Rows.Add( "t2", 11, 66 );
dt.Rows.Add( "t3", 88, 99 );
dt.Rows.Add( "t3", 33, 33 );

string[] result = dt.Rows
                    .Cast<DataRow>( )
                    .Select( r => r.Field<string>( "devID" ) )
                    .Distinct( )
                    .ToArray( );

Answer 3

devID devName kk vv

t1 mmm 11 22

t1 mmm 22 22

t2 nnn 55 66

t3 aaaa 88 99

t3 aaaa 33 33

==>

[{devID="T1",devName="mmm"},

{devID="T2",devName="nnn"},

{devID="T3",devName="mmm"},

]

For this situtation? Thanks.

Answer 4

'I used this in vb.net.

 Dim drSelect() As DataRow = dtMain.Select()
 Dim drGroup = drSelect.GroupBy(Function(row) row(columName))
 Dim arrGroup = drGroup.ToArray