view_csv.R

#' Create a database connection from a CSV file. Internal only function.
#' @noRd
#'
#' @param csv_file_path A string. The csv file path.
#' @param table_name A string. The name of the table in the duckdb database.
#'
#' @importFrom duckdb duckdb
#' @importFrom DBI dbConnect
#' @importFrom DBI dbWriteTable
#' @importFrom readr read_csv
#'
#' @return A DBI database connection object
#'
create_csv_con <- function(csv_file_path, table_name = "csv_file"){

  # Create duckdb instance
  drv <- duckdb::duckdb()
  con <- DBI::dbConnect(drv)

  # Read csv file
  csv_data <- readr::read_csv(
    csv_file_path,
    show_col_types = FALSE
  )

  # Write to db
  DBI::dbWriteTable(
    con,
    table_name,
    csv_data,
    overwrite = TRUE,
    temporary = FALSE,
    row.names = FALSE
  )

  return (con)
}

#' View CSV
#' @description Upload a csv file to a in-memory duckdb database and write queries
#'  against it.
#'
#' @param csv_file_path A string. The csv file path.
#' @param table_name A string. The name of the table in the duckdb database.
#'
#' @return A shiny app instance.
#' @export
#'
view_csv <- function(csv_file_path, table_name = "csv_file"){

  con <- create_csv_con(
    csv_file_path,
    table_name = "csv_file"
  )

  # View file
  octopus::view_database(con)
}