r-sqldf 0.4-11 Manipulate R data frames using SQL
sqldf function is typically passed a single argument which is an SQL select statement where the table names are ordinary R data frame names.
sqldf transparently sets up a database, imports the data frames into that database, performs the SQL statement and returns the result using a heuristic to determine which class to assign to each column of the returned data frame. The
read.csv.sql functions can also be used to read filtered files into R even if the original files are larger than R itself can handle.