Re: [R] For loop and sqldf

From: Jeff Newmiller <jdnewmil_at_dcn.davis.ca.us>
Date: Fri, 29 Apr 2011 17:08:32 -0700

Putting SQL columns/variables into square brackets is valid syntax for sqlite. Expecting sqlite to share variables with R is not, so there was only one necessary change.



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David Winsemius <dwinsemius_at_comcast.net> wrote:

On Apr 29, 2011, at 4:27 PM, mathijsdevaan wrote: > Hi list, > > Can anyone tell my why the following does not work? Thanks a lot! > Your help > is very much appreciated. > > DF = data.frame(read.table(textConnection(" B C D E F G > 8025 1995 0 4 1 2 > 8025 1997 1 1 3 4 > 8026 1995 0 7 0 0 > 8026 1996 1 2 3 0 > 8026 1997 1 2 3 1 > 8026 1998 6 0 0 4 > 8026 1999 3 7 0 3 > 8027 1997 1 2 3 9 > 8027 1998 1 2 3 1 > 8027 1999 6 0 0 2 > 8028 1999 3 7 0 0 > 8029 1995 0 2 3 3 > 8029 1998 1 2 3 2 > 8029 1999 6 0 0 1"),head=TRUE,stringsAsFactors=FALSE)) list<-sort(unique(DF$C)) ; require(sqldf); data <-list() # added inits > for (t in 1:length(list)) > { > year = as.character(list[t]) > data[year]<-sqldf('select * from DF where C = [year]') #I see you have already gotten a workable answer, but thought you might want to see if this would work: data[year]<-sqldf(paste('select * from DF where C = ', year, sep="") ) # Two changes ... let `year` get evaluated and don't put `year` in brack  ets. >

} > > data $`1995` [1] 8025 8026 8029 $`1996` [1] 8026 $`1997` [1] 8025 8026 8027 $`1998` [1] 8026 8027 8029 $`1999` [1] 8026 8027 8028 8029 > I am trying to split up the data.frame into 5 new ones, one for > every year. > > > -- David Winsemius, MD West Hartford, CT_____________________________________________
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