old_source/R/read_sql.R

In kamapu/gisrepos: Repositories of Spatial Data Sets for Environmental Sciences

#' @name read_sql
#' 
#' @title Read SQL scripts and split it in SQL statements
#' 
#' @details 
#' SQL scripts may mix SQL statements with comments. This function extract the
#' respective statements and split them into a list, where each element is a
#' statement.
#' 
#' @param file A character value indicating the path to the script that have to
#'     be read.
#' @param end Symbol set at the end of a statement (semicolon by default).
#' @param comment Symbol used to start a comment in script (two dashes by
#'     default).
#' @param ... Further arguments passed to [readLines()].
#' 
#' @author Miguel Alvarez
#' 
#' @export read_sql
#' 
read_sql <- function(file, end=";", comment="--", ...) {
	Query <- readLines(file, ...)
	Query <- Query[!(nchar(Query) == 0 | grepl(comment, Query, fixed=TRUE))]
	Query <- paste0(Query, "\n")
	idx <- grepl(end, Query, fixed=TRUE)
	idx <- c(0, cumsum(idx[-length(idx)]))
	Query <- split(Query, idx)
	names(Query) <- NULL
	return(Query)
}