R/bigquery-dataset.R

In madedotcom/retl: Support for common ETL operations and connections

#' Dataset manipulation functions
#'
#' @rdname bqDataset
#'
#' @export
#' @param dataset name of the dataset
#' @param project name of the project
#' @return `bqDatasetExists()` - returns TRUE if dataset exists
bqDatasetExists <- function(dataset = bqDefaultDataset(),
                            project = bqDefaultProject()) {
  bqAuth()
  ds <- bq_dataset(project, dataset)
  bq_dataset_exists(ds)
}

#' @rdname bqDataset
#' @export
#' @param dataset name of the dataset
#' @param project name of the project
#' @param location location of the dataset
bqCreateDataset <- function(dataset = bqDefaultDataset(),
                            project = bqDefaultProject(),
                            location = bqDefaultLocation()) {
  bqAuth()
  if (!bqDatasetExists(dataset, project)) {
    bq_dataset_create(
      bq_dataset(
        project = project,
        dataset = dataset
      ),
      location = location
    )
  } else {
    message("Dataset does already exist: ", dataset)
  }
}

#' @rdname bqDataset
#' @details `bqDeleteDataset()` - You can protect dataset
#'   from programmatic deletion by adding `delete:never` label (key:value) to it.
#' @export
#' @param delete.contents removes all content from the dataset if is set to TRUE
bqDeleteDataset <- function(dataset = bqDefaultDataset(),
                            project = bqDefaultProject(),
                            delete.contents = FALSE) {
  bqAuth()

  if (bqDatasetExists(dataset, project)) {
    assert_that(!bqProtectedDataset(dataset, project))

    bq_dataset_delete(
      bq_dataset(
        project = project,
        dataset = dataset
      ),
      delete_contents = delete.contents
    )
  } else {
    message("Dataset does not exist and will not be deleted: ", dataset)
  }

}

#' Gets list of tables for a given dataset
#' @export
#' @rdname bqDataset
bqDatasetTables <- function(dataset = bqDefaultDataset(),
                            project = bqDefaultProject()) {
  bq_dataset_tables(
    bq_dataset(
      project = project,
      dataset = dataset
    )
  )
}

#' Gets meta of given dataset
#' @rdname bqDatasetLocation
#' @export
#' @param dataset name of the dataset
#' @param project name of the project
bqDatasetLocation <- function(dataset = bqDefaultDataset(),
                          project = bqDefaultProject()) {
  meta <- bq_dataset_meta(
    bq_dataset(
      project = project,
      dataset = dataset
    )
  )
  meta$location
}

#' Checks whether dataset has delete:never label pair attached
#' @noRd
bqProtectedDataset <- function(dataset, project) {
  meta <- bq_dataset_meta(
    bq_dataset(
      project = project,
      dataset = dataset
    ),
    fields = c("labels")
  )
  if (length(meta) > 0) {
    delete <- meta$labels$delete
    if (!is.null(delete) && delete == "never") {
      TRUE
    }
    else {
      FALSE
    }
  }
  else {
    FALSE
  }
}

#' Copies all tables from one dataset to another
#' through schema definitions
#'
#' @export
#' @param from dataset object created by bigrquery::bq_dataset()
#' @param to dataset object created by bigrquery::bq_dataset()
bqCopyDatasetSchema <- function(from, to) {

  tables <- bq_dataset_tables(from)
  lapply(tables, function(x) {
    to <- bq_table(to$project, to$dataset, x$table)
    bqCopyTableSchema(x, to)
  })

}