sqldf has some facilities for Date class but has no knowledge of date class.
See example 7b on home page: http://sqldf.googlecode.com and here is a second example: > DF <- data.frame(D = as.Date(c("21DEC2006","15DEC2006"), "%d%b%Y")) > DF D 1 2006-12-21 2 2006-12-15 > sqldf("select * from DF") D 1 2006-12-21 2 2006-12-15 On Tue, Jan 6, 2009 at 1:09 PM, <si...@ntlworld.com> wrote: > Hello, > > I am having trouble with retrieving some data in queries involve with > variables > with data type "date". See the enclosed example: > > ll<-c("21DEC2006","15DEC2006") > ss<-data.frame(ll) > ss<-transform(ss,ll=as.date(as.character(ll))) > (ss) > ll > 1 17156 > 2 17150 > > tt<-sqldf("select ll from ss") > > (tt) >> > ll > 1 NA > 2 NA > >> str(ss) > 'data.frame': 2 obs. of 1 variable: > $ ll:Class 'date' int [1:2] 17156 17150 > >> str(tt) > 'data.frame': 2 obs. of 1 variable: > $ ll:Class 'date' int [1:2] NA NA > > So all the elements of ll (of tt) has been converted into NA. Is there anyway > that I can query the variables with "date" data type using sqldf? > > > Many Thanks, > > Si. > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
