sql - Return rows with both NA and a value at once -

i have df

id <- c(101,102,103,104)  status <- c('p','f_avg','f_sig',na)  df <- data.frame(id,status) 

i trying filter failed ones , return both pass , na not able so. know it's basic question please bear me , me out.

i tried following

df1 <-  sqldf("select * df               status not 'f%'") 

and returns 1 observation , row1 'p' need row4 'na'.

df1 <-  sqldf("select * df               (status not 'f%'               or status null)") 

output:

   id status 1 101      p 2 104   <na> 

using dplyr:

library(dplyr) filter(df, !grepl("^f", status))