arith-methods: Arithmetic Operators for 'db.obj' objects

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

Arithmetic Operators for db.obj objects

Description

These binary operators perform arithmetic on db.obj objects

Usage

## 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,ANY'
e1 - e2
## 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,db.obj'
e1 %% e2
## S4 method for signature 'db.obj,db.obj'
e1 %/% e2
## S4 method for signature 'db.obj,db.obj'
e1 ^ e2
## S4 method for signature 'numeric,db.obj'
e1 + e2
## S4 method for signature 'character,db.obj'
e1 + e2
## S4 method for signature 'numeric,db.obj'
e1 - e2
## S4 method for signature 'character,db.obj'
e1 - e2
## S4 method for signature 'numeric,db.obj'
e1 * e2
## S4 method for signature 'numeric,db.obj'
e1 / e2
## S4 method for signature 'numeric,db.obj'
e1 %% e2
## S4 method for signature 'numeric,db.obj'
e1 %/% e2
## S4 method for signature 'numeric,db.obj'
e1 ^ e2
## S4 method for signature 'db.obj,numeric'
e1 + e2
## S4 method for signature 'db.obj,character'
e1 + e2
## S4 method for signature 'db.obj,numeric'
e1 - e2
## S4 method for signature 'db.obj,character'
e1 - e2
## S4 method for signature 'db.obj,numeric'
e1 * e2
## S4 method for signature 'db.obj,numeric'
e1 / e2
## S4 method for signature 'db.obj,numeric'
e1 %% e2
## S4 method for signature 'db.obj,numeric'
e1 %/% e2
## S4 method for signature 'db.obj,numeric'
e1 ^ e2

Arguments

e1, e2

numeric or db.obj object.

Value

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

Note

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

"-" and "+" support computing the arithmetic computations between dates, timestamps, times etc.

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

x$rings <- (x$rings + 2.3) * 3 # change the values

x$area <- x$length * x$height # add a new column

lk(x$area, 10) # view the actual values computed in database

## ----------------------------------------------------------------------

db.disconnect(cid, verbose = FALSE)

## End(Not run)

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