Package 'mongopipe'

Create or append a mongo aggregation stage

Description

Create or append a mongo aggregation stage

Usage

add_stage(x, ...)

## Default S3 method:
add_stage(x, ...)

## S3 method for class 'mongopipe'
add_stage(x, type, ...)

Arguments

x	Object of class mongo or mongo_pipe
...	query
type	Name of the stage.

Value

Object of type mongopipe.

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Conditional expression ($cond)

Description

Evaluates a boolean expression to return one of the two specified return expressions.

Usage

condition(test, yes, no)

Arguments

test	Expression which returns a boolean value.
yes	Return this if the test returns true.
no	Return this if the test returns false.

Value

Return a list for using in mongopipe.

Examples

## Not run: 
cond <- condition(test = list("$isArray"="$chart"),
                  yes = list("$size"="$chart"),
                  no = 0)
jsonlite::toJSON(cond)

## End(Not run)

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Pipeline Stages

Description

These functions translate R code to json readably by Mongodb.

Usage

match(x, ...)

## S3 method for class 'mongopipe'
match(x, ...)

field(x, ...)

## S3 method for class 'mongopipe'
field(x, ...)

lookup(x, ...)

## S3 method for class 'mongopipe'
lookup(x, from, local_field = from, foreign_field = "_id", as = from, ...)

unwind(x, ...)

## S3 method for class 'mongopipe'
unwind(x, field, ...)

limit(x, ...)

## S3 method for class 'mongopipe'
limit(x, limit, ...)

project(x, ...)

## S3 method for class 'mongopipe'
project(x, ...)

Arguments

x	Object of class mongopipe
...	list object
from	Collection to join
local_field	Field from the input documents
foreign_field	Field from the documents of the "from" collection
as	Name of output array field (Default: from)
field	Field to unwind.
limit	Integer to limit the number of documents.

Value

Object of type mongopipe.

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Mongopipe

Description

Mongopipe

Usage

mongopipe()

Value

Object of type mongopipe.

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