R/check_database_connection.r

In tomasgreif/mondrianr: Create Mondrian schema in R

#' Check database existence
#'
#' Checks if database exists for given data engine and connection. Function returns \code{TRUE} when
#' database exists and \code{FALSE} otherwise.
#' 
#' @param engine See function \code{\link{create_schema}} for details.
#' @param con See function \code{\link{create_schema}} for details.
#' @examples \dontrun{
#' check_database_connection('PostgreSQL',c('usr','pwd','db','host','port'))
#' }

check_database_connection <- function(engine, con) {
  
  if(engine=='PostgreSQL') {
    
    options(sqldf.RPostgreSQL.user      = con[1], 
            sqldf.RPostgreSQL.password  = con[2],
            sqldf.RPostgreSQL.dbname    = con[3],
            sqldf.RPostgreSQL.host      = con[4], 
            sqldf.RPostgreSQL.port      = con[5])
    
    valid_connection <- tryCatch(sqldf("select TRUE;",drv='PostgreSQL'), error=function(cond) FALSE)        
    
  }
    
    valid_connection
}