| fetch-methods {RMySQL} | R Documentation |
This method is a straight-forward implementation of the corresponding generic function.
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).
MySQLResult object.
n = -1 to retrieve all pending records;
use a value of n = 0 for fetching the default number
of rows fetch.default.rec defined in the
MySQL initialization invocation.
See the Database Interface definition document
DBI.pdf in the base directory of this package
or http://stat.bell-labs.com/RS-DBI.
MySQL,
dbConnect,
dbSendQuery,
dbGetQuery,
dbClearResult,
dbCommit,
dbGetInfo,
dbReadTable.
## Not run:
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)
## End(Not run)