R/db-in_transaction.R

In tjpalanca/dbtools: Database Tools for R

#' @title Check whether connection is in transaction
#'
#' @description
#' Transactions are important to ensuring that database writes are predictable.
#'
#' @param conn (DBIConnection) object
#'
#' @family Extra DBI Methods
#' @export
dbInTransaction <- function(conn) {

  UseMethod("dbInTransaction")

}

#' @export
dbInTransaction.PqConnection <- function(conn) {

  identical(
    dbGetQuery(conn, "SELECT txid_current()"),
    dbGetQuery(conn, "SELECT txid_current()")
  )

}

#' @export
dbInTransaction.default <- function(conn) {

  # Attempt to start a transaction
  start <- try(dbBegin(conn), silent = TRUE)

  if (inherits(start, "try-error")) {
    # If failed, then inside a transaction, return TRUE
    TRUE
  } else {
    # If not, then rollback the transaction create and return FALSE
    dbRollback(conn)
    FALSE
  }

}