R/postgresql_dbconnection.R

In OB7-IRD/furdeb: FUnctions for R DEvelopment and Beyond!

#' @name postgresql_dbconnection
#' @title Connection to a PostgreSQL database
#' @description This function able to establish a connection with a PostgreSQL database.
#' @param db_user {\link[base]{character}} expected. Login or username for the database connection.
#' @param db_password {\link[base]{character}} expected. Password for the database connection.
#' @param db_dbname {\link[base]{character}} expected. Name/identification of the database.
#' @param db_host {\link[base]{character}} expected. Host adress of the database.
#' @param db_port {\link[base]{integer}} expected. Identification of the port.
#' @return The function return a list.
#' @importFrom RPostgreSQL dbConnect
#' @importFrom DBI dbDriver
#' @importFrom codama r_type_checking
#' @export
postgresql_dbconnection <- function(db_user,
                                    db_password,
                                    db_dbname,
                                    db_host,
                                    db_port) {
  # 1 - Arguments verification ----
  # db_user argument checking
  if (codama::r_type_checking(r_object = db_user,
                              type = "character",
                              length = 1L,
                              output = "logical") != TRUE) {
    return(codama::r_type_checking(r_object = db_user,
                                   type = "character",
                                   length = 1L,
                                   output = "message"))
  }
  # db_password argument checking
  if (codama::r_type_checking(r_object = db_password,
                              type = "character",
                              length = 1L,
                              output = "logical") != TRUE) {
    return(codama::r_type_checking(r_object = db_password,
                                   type = "character",
                                   length = 1L,
                                   output = "message"))
  }
  # db_dbname argument checking
  if (codama::r_type_checking(r_object = db_dbname,
                              type = "character",
                              length = 1L,
                              output = "logical") != TRUE) {
    return(codama::r_type_checking(r_object = db_dbname,
                                   type = "character",
                                   length = 1L,
                                   output = "message"))
  }
  # db_host argument checking
  if (codama::r_type_checking(r_object = db_host,
                              type = "character",
                              length = 1L,
                              output = "logical") != TRUE) {
    return(codama::r_type_checking(r_object = db_host,
                                   type = "character",
                                   length = 1L,
                                   output = "message"))
  }
  # db_port argument checking
  if ((codama::r_type_checking(r_object = db_port,
                               type = "integer",
                               length = 1L,
                               output = "logical")
       | codama::r_type_checking(r_object = db_port,
                                 type = "numeric",
                                 length = 1L,
                                 output = "logical")) != TRUE) {
    return(cat(format(x = Sys.time(),
                      "%Y-%m-%d %H:%M:%S"),
               " - Error, invalid \"db_port\", type integer or numeric expected.\n"))
  }
  # 2 - Global process ----
  # connection to PostgreSQL database
  postgresql_db_connection <- list("database_name" <- db_dbname,
                                   "connection_information" <- RPostgreSQL::dbConnect(DBI::dbDriver("PostgreSQL"),
                                                                                      user = db_user,
                                                                                      password = db_password,
                                                                                      dbname = db_dbname,
                                                                                      host = db_host,
                                                                                      port = as.integer(x = db_port)))
  return(postgresql_db_connection)
}