var Query = from rowData in dtWorkers.AsEnumerable() where rowData.Field<string>("FirstName") == "Kevin" || rowData.Field<decimal>("Salary") > 90000 select rowData;If you query against a typed datatable...
var Query = from rowData in dtWorkers.AsEnumerable() where rowData.FirstName == "Kevin" || rowData.Salary > 90000 select rowData;Which would you prefer?