Bulk download database tables

Usage

import_db_tables(
  tablevec = getOption("drivesR.default.tablevec"),
  fetch_option = c("download.save", "download.only", "save.only", "upload")[1],
  save_option = c("list", "rds", "csv")[1],
  savedir = ".",
  savename = "drives"
)

Arguments

tablevec

A vector of table names to download. If NULL, the function downloads all DRIVES tables available to the user.

fetch_option

Indicates how tables are fetched and stored. Options are: "download.save": Tables are imported via Directus API and saved as a list object in an Rda file. "download.only": Tables are imported via the Directus API into an object in the global environment. "save.only": Tables are downloaded one-by-one and saved to the local path, without remaining in the global environment. This may be helpful for systems with limited working memory. "upload": The function loads tables from the path specified by savedir and savename into a list in the global environment. Because the download step takes a while, this option saves time when re-running a the script.

save_option

Determines how files are saved on the local system. Options are "list" (the default), "rds", and "csv". The "list" option combines tables into a single named list, db, saved as an RData file. The "rds" and "csv" options save each table to a separate R data or csv file within the directory specified under savedir. Although the list option is more convenient for coding, it requires sufficient RAM to store all the data in working memory. If working memory is limiting, it may be better to load tables individually, as needed.

If the fetch_option is "upload", the save_option should match how they are stored in the local file system.

savedir

Directory path for saving locally. Defaults to the working directory.

savename

File prefix for saving locally. If the save_option is "list", this is the entire file name, excluding extensions. Defaults to "drives". If the save_option is "rds" or "csv", the file name will be the prefix followed by the table name, separated by "_" (e.g., drives_crop_yields.csv).

Value

A named list of DRIVES database tables.

Examples

# importing tables to a list in the R envirnoment without saving:
# not run: db <- import_db_tables(fetch_option = "download.only",save_option = "list")

# saving tables to separate files without keeping them in the R environment:
# not run: db <- import_db_tables(fetch_option = "save.only",save_option = "csv")
# in this case, the object db will be NULL.

# importing tables into a list in the R envinvment while saving as separate files:
# not run: db <- import_db_tables(fetch_option = "download.only",save_option = "csv")
 
# uploading previously-saved tables into a named list:
 # not run: db <- import_db_tables(fetch_option = "upload",save_option = "csv")