With this hook, one can write SQL statements in chunks

These statements will be transmitted to a Sybase server using the jTDS driver

Results are printed in html

To be used in an .Rmd file to generate a html_document

```{r setup, include=FALSE}
SybaseGetQuery <- function(requete.simple, db) {
  require(RJDBC)
  require(htmltools)
  statement <- paste(unlist(requete.simple), collapse="\n")
  conn_string <- sprintf("jdbc:jtds:sybase://%s:%s/%s;user=%s;password=%s",
                         server_sybase, port, db, user, password)
  drv <- JDBC("net.sourceforge.jtds.jdbc.Driver", loc_jtds, "`")
  conn <- dbConnect(drv, conn_string)
  tryCatch(resultat <- dbGetQuery(conn, statement = statement),
           finally = dbDisconnect(conn))
  return(resultat)
}

knitr::opts_hooks$set(sybase = function(options) {
  if (!is.null(options$sybase)) {
    options$eval <- FALSE
    options$echo <- TRUE
    options$results <- 'asis'
    options$`.class` <- "sql"
  }
  options
})

knitr::knit_hooks$set(sybase = function(before, options, envir) {
  if (before) {
  }
  else {
    paste0(
      # Print the query result in an html format:
      knitr::kable(
        SybaseGetQuery(options["code"], options$sybase),
        format = "html",
        table.attr = 'class="responsive-table highlight"', # Class for materialize.css
        row.names = TRUE,
        format.args = list(big.mark = " ", decimal.mark = ",", big.interval = 3L)), # European format
      collapse = NULL
  )}
})

loc_jtds <- "loc_jtds"
server_sybase <- "server_name"
port <- "a_port_number"
user <- "username"
password <- "password"

knitr::opts_chunk$set(sybase="db_name")
```