logical-methods: Logical operations for 'db.obj' objects

In greenplum-db/GreenplumR: A Fast, Easy-to-Use Tool for Manipulating Tables in Databases

Logical operations for db.obj objects

Description

These binary operators perform logical operations on db.obj objects

Usage

## S4 method for signature 'db.obj' 

## S4 method for signature 'db.obj'
!x 

## S4 method for signature 'db.obj,db.obj'
e1 & e2 

## S4 method for signature 'db.obj,db.obj'
e1 | e2 

## S4 method for signature 'db.obj,logical'
e1 & e2 

## S4 method for signature 'db.obj,logical'
e1 | e2 

## S4 method for signature 'logical,db.obj'
e1 & e2 

## S4 method for signature 'logical,db.obj'
e1 | e2 

Arguments

e1, e2	logical or db.obj object.
x	db.obj object.

Value

db.Rquery object, which contains the SQL query that computes the logical operations.

Note

A meaningful expression is generated only when the .col.data_type is "boolean", otherwise a "NULL" value is generated.

Author(s)

Author: Predictive Analytics Team at Pivotal Inc.

Maintainer: Frank McQuillan, Pivotal Inc. [e-mail]

See Also

db.Rquery contains a SQL query that does the operations.

Examples

## Not run: 
## get the help for a method
## help("|,db.obj,db.obj-method")



## 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)

## create a table from the example data.frame "abalone"
x <- as.db.data.frame(abalone, conn.id = cid, verbose = FALSE)

lk(x$rings[x$length > 10 & x$height < 2,])

db.disconnect(cid, verbose = FALSE)

## End(Not run)

greenplum-db/GreenplumR documentation built on Sept. 2, 2023, 8:09 a.m.