cbind and match in data.frame structure

user_5509273 0
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As I am new to the data.table package, I would like to replicate what I would normally do in a data.frame structure below, to a data.table structure.

Dta     <- data.frame(Customer = c("Javier","Oscar","Ivan","Peter"),Type_of_Customer=LETTERS[c(1,1:3)])
Dtb     <- data.frame(Customer = c("Javier","Oscar","Ivan","Jack"),Zone=5:8,District=100:103)
Result  <- cbind(Dtb[match(Dtb[,"Customer"],Dta[,"Customer"]),c("Zone","District")],Dta)


ww     <- which(is.na(Result[,"Zone"]))
if(length(ww) > 0){
  Result[ww,"Zone"] <- "Not in Dtb"
}

ww     <- which(is.na(Result[,"District"]))
if(length(ww) > 0){
  Result[ww,"District"] <- "Not in Dtb"
  }

So If I had Dta and Dtb as data.table structure, what would be the way to go? (Note: In the real sample I have around 10 million rows so I would need the more time-efficient solution)

Dta     <- data.table(Custumer = c("Javier","Oscar","Ivan","Peter"),Type_of_Customer=LETTERS[c(1,1:3)])
Dtb     <- data.table(Custumer = c("Javier","Oscar","Ivan","Jack"),Zone=5:8,District=100:103)

Thanks.

data.table data-manipulation dataframe r
1 Answers

We can use a join on thee 'Custumer' and replace the NA elements with 'Not in 'Dtb' string

Dtb[Dta, on = .(Custumer)][, c("Zone", "District") := 
    .(as.character(Zone), as.character(District))
     ][is.na(Zone), c("Zone", "District") := "Not in Dtb"][]
#    Custumer       Zone   District Type_of_Customer
#1:   Javier          5        100                A
#2:    Oscar          6        101                A
#3:     Ivan          7        102                B
#4:    Peter Not in Dtb Not in Dtb                C
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