如何在data.frame列中使用IF计数，这些单元格的缺失值（NA）？

I have a data.frame object named "selPOGs2". In this data.frame I'm adding one column "GeneID". After I transform the data.frame to character, I add data in the "GeneID" column. These data are returned from a query to a database. If no answer is found in the database, then in the corresponding cell in GeneID column a NA is placed. The column looks something like this:I have a data.frame object named "selPOGs2". In