graph_join_plan: Build a draw-able specification of the join diagram

In rquery: Relational Query Generator for Data Manipulation at Scale

Build a draw-able specification of the join diagram

Description

Please see vignette('DependencySorting', package = 'rquery') and vignette('joinController', package= 'rquery') for more details.

Usage

graph_join_plan(columnJoinPlan, ..., groupByKeys = TRUE, graphOpts = NULL)

Arguments

columnJoinPlan	join plan
...	force later arguments to bind by name
groupByKeys	logical if true build key-equivalent sub-graphs
graphOpts	options for graphViz

Value

grViz diagram spec

See Also

describe_tables, build_join_plan, actualize_join_plan

Examples

if (requireNamespace("DBI", quietly = TRUE) && requireNamespace("RSQLite", quietly = TRUE)) {
  # note: employeeanddate is likely built as a cross-product
  #       join of an employee table and set of dates of interest
  #       before getting to the join controller step.  We call
  #       such a table "row control" or "experimental design."
  my_db <- DBI::dbConnect(RSQLite::SQLite(), ":memory:")
  RSQLite::initExtension(my_db)
  tDesc <- example_employee_date(my_db)
  # fix order by hand, please see rquery::topo_sort_tables for
  # how to automate this.
  ord <- match(c('employeeanddate', 'orgtable', 'activity', 'revenue'),
               tDesc$tableName)
  tDesc <- tDesc[ord, , drop=FALSE]
  columnJoinPlan <- build_join_plan(tDesc, check= FALSE)
  # unify keys
  columnJoinPlan$resultColumn[columnJoinPlan$resultColumn=='id'] <- 'eid'
  # look at plan defects
  print(paste('problems:',
              inspect_join_plan(tDesc, columnJoinPlan)))
  diagramSpec <- graph_join_plan(columnJoinPlan)
  # # to render as JavaScript:
  # if(requireNamespace("DiagrammeR", quietly = TRUE)) {
  #   print(DiagrammeR::grViz(diagramSpec))
  # }
  DBI::dbDisconnect(my_db)
  my_db <- NULL
}

rquery documentation built on Aug. 20, 2023, 9:06 a.m.