Proxy interface {RPgSQL} | R Documentation |
bind.db.proxy
returns a proxy object bound to a database
table.
row.names
returns a name for each row in the proxy frame.
dimnames
returns the dimension names.
as.list
converts a proxy frame to a list.
as.matrix
converts a proxy frame to a matrix.
[[.db.proxy
extracts columns, rows and subsets of the proxy
frame.
[.db.proxy
extracts columns, rows and subsets of the proxy
frame.
as.data.frame
convert proxy to data frame.
db.has.row.names
were row names stored in the database
table?
names
get column names.
dim
get frame dimensions.
summary
summarize proxy frame.
print
print some of the proxy frame.
db.table.name
get the database table name from the proxy frame.
bind.db.proxy(table.name, vacuum=F) row.names(proxy) dimnames(proxy) as.list(proxy) as.matrix(proxy) proxy[[row, col]] proxy[row, col] as.data.frame(proxy) db.has.row.names(proxy) names(proxy) dim(proxy) summary(proxy) print(proxy) db.table.name(proxy)
table.name |
A character string with the name of a table |
vacuum |
If true, update table statistics |
row |
A row index |
col |
A column index |
proxy |
A db.proxy object |
Proxy object inherit from class "data.frame". In theory, a proxy object should behave in every way like a data frame. Unfortunately, this is difficult the way objects are handled internally by R.
bind.db.proxy
returns a proxy object. No data, other than the
table name, host and database name, are stored in the proxy object.
In order to make proxy objects work, I had to make
row.names
a generic object method. This may break other
packages.
Timothy H. Keitt
if (db.connection.open()) { data(airquality) rpgsql.test.data <- airquality rm(airquality) db.write.table(rpgsql.test.data, no.clobber=F) bind.db.proxy("rpgsql.test.data") summary(rpgsql.test.data) rpgsql.test.data rpgsql.test.data[50:55,] rpgsql.test.data[["Ozone"]] #This doesn't work rpgsql.test.data$Ozone #Clean up db.rm("rpgsql.test.data", ask=F) }