RMySQL (version 0.9-3)

fetch-methods: Fetch records from a previously executed query

Description

This method is a straight-forward implementation of the corresponding generic function.

Details

The RMySQL implementations retrieves only n records, and if n is missing it only returns up to fetch.default.rec as specified in the call to MySQL (500 by default).

References

See the Database Interface definition document DBI.pdf in the base directory of this package or http://stat.bell-labs.com/RS-DBI.

See Also

MySQL, dbConnect, dbSendQuery, dbGetQuery, dbClearResult, dbCommit, dbGetInfo, dbReadTable.

Examples

drv <- dbDriver("MySQL")
con <- dbConnect(drv, user = "opto", password="pure-light", 
                 host = "localhost", dbname="lasers")
res <- dbSendQuery(con, statement = paste(
                      "SELECT w.laser_id, w.wavelength, p.cut_off",
                      "FROM WL w, PURGE P", 
                      "WHERE w.laser_id = p.laser_id",
                      "ORDER BY w.laser_id"))
# we now fetch the first 100 records from the resultSet into a data.frame
data1 <- fetch(res, n = 100)   
dim(data1)

dbHasCompleted(res)

# let's get all remaining records
data2 <- fetch(res, n = -1)