Thanks for this! This is even simpler than using !is.null(): xmat <- as.data.frame(matrix(NA, 2, 3)) try(xmat[i, 2:3] <- dbGetQuery(...), silent = TRUE)
Best wishes, Mikkel --- Uwe Ligges <[EMAIL PROTECTED]> wrote: > Mikkel Grum wrote: > > > I have a situation where I'm filling out a > dataframe > > from a database. Sometimes the database query > doesn't > > get anything, so I end up trying to place NULL in > the > > dataframe like below. > > > > > >>temp <- NULL > >>xmat <- as.data.frame(matrix(NA, 2, 3)) > >>xmat[1, 2:3] <- temp > > > > Error in if (m < n * p && (n * p)%%m) > > stop(gettextf("replacement has %d items, need %d", > : > > missing value where TRUE/FALSE needed > > > > I can't get the programme to accept that sometimes > > what the query looks for just doesn't exist, and I > > just want to move on to the next calculation > leaving > > the dataframe with a missing value in the given > cell. > > It's a real show stopper and I haven't found a way > > round it. > > > See ?try > > Uwe Ligges > > > > Best wishes, > > Mikkel > > > > PS. I'm using dbGetQuery to query an SQLite > database. > > > > ______________________________________________ > > R-help@stat.math.ethz.ch mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html