compare-methods: Comparison Operators for 'db.obj' objects

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

Comparison Operators for db.obj objects

Description

These binary operators perform comparison 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,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 'character,db.obj'
e1 > e2
## S4 method for signature 'character,db.obj'
e1 < e2
## S4 method for signature 'character,db.obj'
e1 >= e2
## S4 method for signature 'character,db.obj'
e1 <= e2
## S4 method for signature 'character,db.obj'
e1 == e2
## S4 method for signature 'character,db.obj'
e1 != e2
## S4 method for signature 'db.obj,character'
e1 > e2
## S4 method for signature 'db.obj,character'
e1 < e2
## S4 method for signature 'db.obj,character'
e1 >= e2
## S4 method for signature 'db.obj,character'
e1 <= e2
## S4 method for signature 'db.obj,character'
e1 == e2
## S4 method for signature 'db.obj,character'
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 'numeric,db.obj'
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
## S4 method for signature 'db.obj,numeric'
e1 != e2
## S4 method for signature 'db.obj,logical'
e1 == e2
## S4 method for signature 'logical,db.obj'
e1 == e2
## S4 method for signature 'db.obj,logical'
e1 != e2
## S4 method for signature 'logical,db.obj'
e1 != e2
## S4 method for signature 'character,db.obj'
grepl(pattern, x, ignore.case = FALSE, perl = FALSE, fixed = FALSE, useBytes = FALSE)

Arguments

e1, e2	numeric, character or db.obj object.
pattern	character string containing a regular expression (or character string for 'fixed = TRUE') to be matched in the given character vector.
x	A db.obj object.
ignore.case	if 'FALSE', the pattern matching is _case sensitive_ and if 'TRUE', case is ignored during matching.
perl	logical. Should perl-compatible regexps be used? Not implemented yet.
fixed	logical. If 'TRUE', 'pattern' is a string to be matched as is. Overrides all conflicting arguments.
useBytes	logical. Not implemented yet.

Value

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

Note

A meaningful expression is generated only when the .col.data_type is "character" or "numeric", 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"
delete("abalone", conn.id = cid)
x <- as.db.data.frame(abalone, "abalone", conn.id = cid, verbose = FALSE)

lk(x[x$length > 10,])

db.disconnect(cid, verbose = FALSE)

## End(Not run)

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