Concatenate Rows into one string

referring to this ^

it throws this error: Assign: Specified cast is not valid.

Assign value: String.Join(",",dt.AsEnumerable().[Select](Function(s) s.Field(Of Double)(“f”)).ToArray())

dt - datatable
f - column

@KP6689

Try this:

     String.Join(",",dt.AsEnumerable().Where(Function(a) a(“ColumnName”)).ToArray)

it throws this error

@KP6689

Please check below thread to resolve this issue.