| dbConnect-methods {RSQLite} | R Documentation |
These methods are straight-forward implementations of the corresponding generic functions.
SQLiteDriver, or
the character string "SQLite" or an SQLiteConnection.
SQLiteConnection object as produced by dbConnect.
PRAGMAs
cache\_size and synchronous when initializing a new
connection (this does not applies, obviously, to cloning an existing
connection).
RSQLite defaults synchronous to 0 (or "OFF"),
although SQLite's default as of 3.2.8 is 2 (FULL).
Possible values for synchronous are 0, 1, or 2 or the
corresponding strings "OFF", "NORMAL", or "FULL".
Users have reported significant speed ups using sychronous=0,
and the SQLite documentation itself implies considerable improved
performance at the very modest risk of database corruption in the
unlikely case of the operating system (not the R application)
crashing. See the SQLite documentation for the full details of this
PRAGMA.
cache\_size can be a positive integer to change
the maximum number of disk pages that SQLite holds in
memory (SQLite's default is 2000 pages).
A connection between R/S-Plus and the embeddable SQLite server is established. Note that since the SQLite is embedded in R/S-Plus, connections are not too resource hungry.
SQLite connections only require the file name where the SQLite
database reside. For details see SQLite.
See the Database Interface definition document
DBI.pdf in the base directory of this package
or http://stat.bell-labs.com/RS-DBI.
SQLite,
dbConnect,
dbSendQuery,
dbGetQuery,
fetch,
dbCommit,
dbGetInfo,
dbReadTable.
## Not run:
# create an SQLite instance and create one connection.
drv <- dbDriver("SQLite")
# open the connection using user, passsword, etc., as
con <- dbConnect(drv, dbname = "sqlite.db")
# Run an SQL statement by creating first a resultSet object
rs <- 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",
"SORT BY w.laser_id")
# we now fetch records from the resultSet into a data.frame
data <- fetch(rs, n = -1) # extract all rows
dim(data)
## End(Not run)