[R] read.csv.sql() to select from a large csv file

Gabor Grothendieck ggrothendieck at gmail.com
Fri Nov 23 17:49:43 CET 2012


On Fri, Nov 23, 2012 at 11:12 AM, Juliane Struve
<juliane_struve at yahoo.co.uk> wrote:
> Dear list,
>
> Dear list,
> I am using read.csv.sql() from the sqldf package to read
> individual-based data from a csv file that is too large for R.
> My original file contains a column called “ID” that
> identifies the individual. I would like to read in data for only
> one individual at a
> time, for example "Bobby".
> read.csv.sql("filename",sql = 'select * from file where ID = “Bobby”') works fine, but
> Name <- "Bobby"
> read.csv.sql("filename",sql = 'select * from file
> where ID = Name') gives me an error message
>  “Error in sqliteExecStatement(con, statement,
> bind.data) :
> RS-DBI driver: (error in statement: no such column: Name)”
>
> I would like to use a variable in the select statement because I have many individuals in the original csv file, is this possible ? I have no experience with sql, perhaps someone can kindly point out how to do this correctly or offer an alternative solution ?

See Example 5 on the sqldf home page:

https://code.google.com/p/sqldf/#Example_5._Insert_Variables


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