subset-methods: Extract a subset of a table or view

Description Usage Arguments Value Author(s) See Also Examples

Description

This function extracts a subset of a db.obj which could either be a db.table or db.view object.

Usage

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## S4 method for signature 'db.obj'
subset(x, subset, select)

Arguments

x

A db.obj (either db.table or db.view) object from which to extract element(s).

subset, select

Indices specifying elements to extract or replace. Indices are ‘numeric’ or ‘character’ vectors or empty (missing) or ‘NULL’. Numeric values are coerced to integer as by ‘as.integer’ (and hence truncated towards zero).

Value

A db.Rquery object is returned which is a SQL query to extract the requested subset.

Author(s)

Author: Predictive Analytics Team at Pivotal Inc.

Maintainer: Frank McQuillan, Pivotal Inc. [email protected]

See Also

[-methods Operator to extract elements

Examples

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## Not run: 


## set up the database connection
## Assume that .port is port number and .dbname is the database name
cid <- db.connect(port = .port, dbname = .dbname, verbose = FALSE)

x <- as.db.data.frame(abalone, conn.id = cid, verbose = FALSE)
lk(x, 10)

lk(x[1:3])
lk(subset(x, 1:3))

db.disconnect(cid, verbose = FALSE)

## End(Not run)

PivotalR documentation built on May 30, 2017, 8:18 a.m.