使用RODBC进行长SQL查询

Question

I have a long SQL query that generates an*5 matrix when executed. I would like to loop through this 5 times, changing the year from 2008 to 2013. This will produce 5 matrices, all with 5 columns but each with a different number of rows. I would like to append each matrix onto each other into one big matrix. I already know that the total number of rows in the big matrix should be 17526.

The current code is like this:

library(RODBC)
conn = odbcConnect(dsn = "database name")

startyear=2008
endyear=2013  
results=data.frame(matrix(ncol = 5, nrow = 17526))

for (i in startyear:endyear) {
query = paste("
SQL CODE
")
results[i] = sqlQuery(conn, query) }

2 Questions:

1. Is there a way to have the paste command not print in the console? The SQL query is over 600 lines and takes a while to print.
2. Any guesses as to why the loop doesn't work, as constructed? If I do not loop but rather set i equal to some year it works.

Answer 1

use rbind , do.call and lapply :

  ret <- lapply(startyear:endyear, function(i) {
                  query = paste("
                            SQL CODE
                          ")
                  sqlQuery(conn, query)
                })
  final <- do.call(rbind, ret)

Or better yet:

final <- do.call(rbind(lapply(
            startyear:endyear, function(i)
                sqlQuery(conn, paste("
                                SQL CODE
                               "))
              )))