Perhaps the sprintf function is what you are looking for. It is one way to insert information from a variable into a string. A couple of other options are paste, paste0, and the gsubfn package, but I think sprintf will be simplest for what you are asking.
On Thu, Aug 16, 2012 at 1:30 PM, Kenneth Rose <kennethros...@gmail.com> wrote: > Hi R community > > I copied a bit of my R code that gets some data from a database. You > won't be able to run the code, but I am a beginner so you will > probably understand what going on. > > I would like to make a variable I can refer to inside the sqlQuery. > Instead of writing the start date and time (ex SP.lokaldatotid >= > '2005-01-01 00:00:00') inside the query I would like to define it in > the beginning of the code, so I don't have to fiddle with a lot of > dates each time I wan't to change it. I would like to do this for a > few of the variables and maybe even make a list/array I can loop > through, so I don't have to write the same code multiple times (for > SYS and DK1). > > I have searched for a solution for two days now, but I am not sure > what it's called and are probably writing the wrong queries :-) > > > Thank you for your help! > > Kenneth > > My code: > > library(xts) > library(RODBC) > > > #Define channnel (i configured my own SYSTEM-DNS, via ODBC) > ch <- odbcConnect("DI2") > > ##################################################################### > ############################## GET DATA ########################## > ##################################################################### > > ############################## SYSTEM spot ########################## > # Hent data fra SQL Server > sys <- sqlQuery (ch, paste("SELECT SP.lokaldatotid, SP.pris FROM > DataIndsamling2.dbo.SpotPriser SP", > "WHERE (SP.omraade_id= 0 AND > SP.lokaldatotid >= '2005-01-01 00:00:00')")) > #Definer dato og tid kolonne > sys$lokaldatotid <- as.POSIXct(sys$lokaldatotid) > > #Make a XTS object > sys_xts <- xts(sys[,-1], order.by=sys[,1]) > > # Recalculate data from hours to daily, monthly and yearly averages > sys_xts_daily <- apply.daily(sys_xts, FUN=mean) > sys_xts_monthly <- apply.monthly(sys_xts, FUN=mean) > sys_xts_yearly <- apply.yearly(sys_xts, FUN=mean) > > > ############################## DK1 spot ############################# > # Hent data fra SQL Server > dk1 <- sqlQuery (ch, paste("SELECT SP.lokaldatotid, SP.pris FROM > DataIndsamling2.dbo.SpotPriser SP", > "WHERE (SP.omraade_id= 5 AND > SP.lokaldatotid >= '2005-01-01 00:00:00')")) > #Definer dato og tid kolonne > dk1$lokaldatotid <- as.POSIXct(dk1$lokaldatotid) > > #Lav om til xts object > dk1_xts <- xts(dk1[,-1], order.by=dk1[,1]) > > #Data omregnet fra time ->> daglig, måned, årlige gennemsnit > dk1_xts_daily <- apply.daily(dk1_xts, FUN=mean) > dk1_xts_monthly <- apply.monthly(dk1_xts, FUN=mean) > dk1_xts_yearly <- apply.yearly(dk1_xts, FUN=mean) > > ______________________________________________ > 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. -- Gregory (Greg) L. Snow Ph.D. 538...@gmail.com ______________________________________________ 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.