skip some rows in read.csv in R

Question

I have a csv file which I read using the following function:

csvData <- read.csv(file=\"pf.csv\", colClasses=c(NA, NA,\"NULL\",NA,\"NULL\",NA,\"NULL\",\"         


        

Answer 1

It is possible using sqldf package, using read.csv.sql

Lets say the contents of sample.csv looks like this:

id,name,age
1,"a",23
2,"b",24
3,"c",23

Now to read only rows where age=23:

require(sqldf)

df <- read.csv.sql("sample.csv", "select * from file where age=23")

df
  id name age
1  1  "a"  23
2  3  "c"  23

It is possible to select necessary columns:

df <- read.csv.sql("sample.csv", "select id, name from file where age=23")
df
  id name
1  1  "a"
2  3  "c"