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

[Juliane Struve]

Rui, Anthony, and Gabor,
 
I got this to work in the end:
 
for(i in length(Names_EastCoast){
name <- Names_EastCoast[i]
sql <- paste("select * from file where ID =
'",name,"'",sep = "")
Data <- read.csv.sql("filename",sql = sql)
}
 
loops through all individuals in the csv file.
 
Thanks a lot for all replies.
 
Juliane   

________________________________
 From: Rui Barradas <ruipbarra...@sapo.pt>

Cc: Rmailinglist <r-help@r-project.org> 
Sent: Friday, 23 November 2012, 11:56
Subject: Re: [R] read.csv.sql() to select from a large csv file
  

Hello,

Try forming the sql statement with paste().

Name <- "Bobby"
sqlstatement <- paste("select * from file where ID = '", Name,
    "'", sep = "")
read.csv.sql("filename", sql = sqlstatement)

Note the opening and closing quotes around the name.

Hope this helps,

Rui Barradas

Em 23-11-2012 16:12, Juliane Struve escreveu:

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 = 
“Bobbyâ€') 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)â€
 
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 ?
Thank you very much and happy Friday,
Juliane 
Dr. Juliane Struve
Fisheries and Aquatic Sciences
7922 NW 71st Street, Gainesville, FL 32653
352-273-3632 (tel)
352-392-3672 (fax)
email:mailto:jstr...@ufl.edu [[alternative HTML version deleted]]  
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