R/query.R

In Kidapt/keda: A Package to Support Exploratory Data Analysis

#' performs a database query
#'
#' performs a database query
#' @param db is the database name
#' @param x is the string representing a SQL query
#' @keywords query
#' @export
#' @examples
#' query(olap, "select * from question_answer limit 6")

query <- function(db, x){
  require(data.table)
  cat(x, "\n")
  t0 = Sys.time()
  h = do.call(db, list())
  x = data.table(dbGetQuery(h, x))
  dbDisconnect(h)
  for (j in grep('_seq$', names(x), value=T)) set(x, j = j, value = as.integer(x[[j]]))
  duration = difftime(Sys.time(), t0)
  uni = attr(duration, "units")
  duration = round(as.numeric(duration), 2)
  cat("query completed in", duration, uni, "\n")
  x
}