Vignettes: offline analogs of betydb-data-access SQL and dplyr examples (using betydata objects)

[dlebauer]

Goal

• Provide user-facing vignettes that show how to do the common SQL and dbplyr workflows from betydb-data-access, but entirely offline using betydata objects.

Inputs

• SQL examples:
  https://github.com/PecanProject/betydb-data-access/blob/master/sqlqueries.md
• dbplyr / dplyr examples:
  https://github.com/PecanProject/betydb-data-access/blob/master/r_dplyr_package.md

Tasks

• Add one two short vignettes that demonstrate any of the useful queries/analyses from the above sources:
  1. sql analogs
     • show the intent of key SQL queries as local dplyr pipelines against traitsview and support tables
     • include at least one example that mimics yieldsview/traitsview style joins but uses packaged objects
  2. dplyr analogs
     • reproduce the structure of the dbplyr/dplyr examples using local objects
     • emphasize “same analysis, no database”
• Keep the examples minimal, stable, and fast.
• no need to duplcate any analyses e.g. it is possible that these overlap or were derived from the manuscript code.

Acceptance criteria

• Both vignettes build under R CMD check.
• Each vignette includes at least 2 concrete examples that a user can copy/paste and adapt.
• No DB/API calls are used.

Non-goals

• No attempt to exactly replicate DB performance or dbplyr translation; goal is pedagogical equivalence.