dbDriver-methods {RPostgreSQL} | R Documentation |
PostgreSQL driver initialization and closing
PostgreSQLDriver
as created by
dbDriver
.
fetch
with the n=
argument.FALSE
.
See the Database Interface definition document
DBI.pdf
in the base directory of this package
or
http://stat.bell-labs.com/RS-DBI.
PostgreSQL
,
dbConnect
,
dbSendQuery
,
dbGetQuery
,
fetch
,
dbCommit
,
dbGetInfo
,
dbListTables
,
dbReadTable
.
## Not run: # create an PostgreSQL instance and set 10000 of rows per fetch. library(RPostgreSQL) drv <- dbDriver("PostgreSQL", fetch.default.records=10000) # Connecting to PostgreSQL with the specified parameters con <- dbConnect(drv,user="usrname",password="passwd",dbname="postgres") # Running the query to obtain the resultset rs <- dbSendQuery(con, "select * from cities where population > 5000") # fetch records into a dataframe. # n = 50 fetched fifty records df <- fetch(rs, n = 50) # n = -1 fetches all the remaining records available df2 <- fetch(rs, n = -1) # Clearing the result set dbClearResult(rs) #This returns a character vector (possibly of zero-length) # table names available on the con connection. dbListTables(con) ## End(Not run)