Minus operation of data frames

Question

I have 2 data frames df1 and df2.

df1 <- data.frame(c1=c(\"a\",\"b\",\"c\",\"d\"),c2=c(1,2,3,4) )
df2 <- data.frame(c1=c(\"         


        

Answer 1

I prefer sqldf package:

require(sqldf)
sqldf("select * from df1 except select * from df2")

##   c1 c2
## 1  a  1
## 2  b  2