subset dataframe with sqldf : i try to subset dataframe using sqlfd but it don't work.can someone explain what don't work?i have processed like this.
> library(sqldf)

 >dataf <- read.csv("zert.csv")

 >agep, pwgt1 are columns of dataf

> dd <- sqldf("select * from dataf where AGEP < 50 and pwgtp1")

>Error in .local(drv, ...) : 

  >Failed to connect to database: Error: Access denied for user 'rodrigue'@'localhost' (using password: NO)
Error in !dbPreExists : invalid argument type
