text: ;;; ob-sql.el --- org-babel functions for sql evaluation
  
  ;; Copyright (C) 2009-2014 Free Software Foundation, Inc.
  
  ;; Author: Eric Schulte
  ;; Keywords: literate programming, reproducible research
  ;; Homepage: http://orgmode.org
  
  ;; This file is part of GNU Emacs.
  
  ;; GNU Emacs is free software: you can redistribute it and/or modify
  ;; it under the terms of the GNU General Public License as published by
  ;; the Free Software Foundation, either version 3 of the License, or
  ;; (at your option) any later version.
  
  ;; GNU Emacs is distributed in the hope that it will be useful,
  ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  ;; GNU General Public License for more details.
  
  ;; You should have received a copy of the GNU General Public License
  ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  
  ;;; Commentary:
  
  ;; Org-Babel support for evaluating sql source code.
  ;; (see also ob-sqlite.el)
  ;;
  ;; SQL is somewhat unique in that there are many different engines for
  ;; the evaluation of sql (Mysql, PostgreSQL, etc...), so much of this
  ;; file will have to be implemented engine by engine.
  ;;
  ;; Also SQL evaluation generally takes place inside of a database.
  ;;
  ;; Header args used:
  ;; - engine
  ;; - cmdline
  ;; - dbhost
  ;; - dbuser
  ;; - dbpassword
  ;; - database
  ;; - colnames (default, nil, means "yes")
  ;; - result-params
  ;; - out-file
  ;; The following are used but not really implemented for SQL:
  ;; - colname-names
  ;; - rownames
  ;; - rowname-names
  ;;
  ;; TODO:
  ;;
  ;; - support for sessions
  ;; - support for more engines (currently only supports mysql)
  ;; - what's a reasonable way to drop table data into SQL?
  ;;
  
  ;;; Code:
  (require 'ob)
  (eval-when-compile (require 'cl))
  
  (declare-function org-table-import "org-table" (file arg))
  (declare-function orgtbl-to-csv "org-table" (table params))
  (declare-function org-table-to-lisp "org-table" (&optional txt))
  
  (defvar org-babel-default-header-args:sql '())
  
  (defconst org-babel-header-args:sql
    '((engine	       . :any)
      (out-file	       . :any)
      (dbhost	       . :any)
      (dbuser	       . :any)
      (dbpassword	       . :any)
      (database	       . :any))
    "SQL-specific header arguments.")
  
  (defun org-babel-expand-body:sql (body params)
    "Expand BODY according to the values of PARAMS."
    (org-babel-sql-expand-vars
     body (mapcar #'cdr (org-babel-get-header params :var))))
  
  (defun dbstring-mysql (host user password database)
    "Make MySQL cmd line args for database connection.  Pass nil to omit that arg."
    (combine-and-quote-strings
     (remq nil
  	 (list (when host     (concat "-h" host))
  	       (when user     (concat "-u" user))
  	       (when password (concat "-p" password))
  	       (when database (concat "-D" database))))))
  
  (defun org-babel-execute:sql (body params)
    "Execute a block of Sql code with Babel.
  This function is called by `org-babel-execute-src-block'."
    (let* ((result-params (cdr (assoc :result-params params)))
           (cmdline (cdr (assoc :cmdline params)))
           (dbhost (cdr (assoc :dbhost params)))
           (dbuser (cdr (assoc :dbuser params)))
           (dbpassword (cdr (assoc :dbpassword params)))
           (database (cdr (assoc :database params)))
           (engine (cdr (assoc :engine params)))
           (colnames-p (not (equal "no" (cdr (assoc :colnames params)))))
           (in-file (org-babel-temp-file "sql-in-"))
           (out-file (or (cdr (assoc :out-file params))
                         (org-babel-temp-file "sql-out-")))
  	 (header-delim "")
           (command (case (intern engine)
                      ('dbi (format "dbish --batch %s < %s | sed '%s' > %s"
  				  (or cmdline "")
  				  (org-babel-process-file-name in-file)
  				  "/^+/d;s/^\|//;s/(NULL)/ /g;$d"
  				  (org-babel-process-file-name out-file)))
                      ('monetdb (format "mclient -f tab %s < %s > %s"
                                        (or cmdline "")
                                        (org-babel-process-file-name in-file)
                                        (org-babel-process-file-name out-file)))
                      ('msosql (format "osql %s -s \"\t\" -i %s -o %s"
                                       (or cmdline "")
                                       (org-babel-process-file-name in-file)
                                       (org-babel-process-file-name out-file)))
                      ('mysql (format "mysql %s %s %s < %s > %s"
  				    (dbstring-mysql dbhost dbuser dbpassword database)
  				    (if colnames-p "" "-N")
                                      (or cmdline "")
  				    (org-babel-process-file-name in-file)
  				    (org-babel-process-file-name out-file)))
  		    ('postgresql (format
  				  "psql -A -P footer=off -F \"\t\"  -f %s -o %s %s"
  				  (org-babel-process-file-name in-file)
  				  (org-babel-process-file-name out-file)
  				  (or cmdline "")))
                      (t (error "No support for the %s SQL engine" engine)))))
      (with-temp-file in-file
        (insert
         (case (intern engine)
  	 ('dbi "/format partbox\n")
  	 (t ""))
         (org-babel-expand-body:sql body params)))
      (message command)
      (org-babel-eval command "")
      (org-babel-result-cond result-params
        (with-temp-buffer
  	  (progn (insert-file-contents-literally out-file) (buffer-string)))
        (with-temp-buffer
  	(cond
  	  ((or (eq (intern engine) 'mysql)
  	       (eq (intern engine) 'dbi)
  	       (eq (intern engine) 'postgresql))
  	   ;; Add header row delimiter after column-names header in first line
  	   (cond
  	    (colnames-p
  	     (with-temp-buffer
  	       (insert-file-contents out-file)
  	       (goto-char (point-min))
  	       (forward-line 1)
  	       (insert "-\n")
  	       (setq header-delim "-")
  	       (write-file out-file)))))
  	  (t
  	   ;; Need to figure out the delimiter for the header row
  	   (with-temp-buffer
  	     (insert-file-contents out-file)
  	     (goto-char (point-min))
  	     (when (re-search-forward "^\\(-+\\)[^-]" nil t)
  	       (setq header-delim (match-string-no-properties 1)))
  	     (goto-char (point-max))
  	     (forward-char -1)
  	     (while (looking-at "\n")
  	       (delete-char 1)
  	       (goto-char (point-max))
  	       (forward-char -1))
  	     (write-file out-file))))
  	(org-table-import out-file '(16))
  	(org-babel-reassemble-table
  	 (mapcar (lambda (x)
  		   (if (string= (car x) header-delim)
  		       'hline
  		     x))
  		 (org-table-to-lisp))
  	 (org-babel-pick-name (cdr (assoc :colname-names params))
  			      (cdr (assoc :colnames params)))
  	 (org-babel-pick-name (cdr (assoc :rowname-names params))
  			      (cdr (assoc :rownames params))))))))
  
  (defun org-babel-sql-expand-vars (body vars)
    "Expand the variables held in VARS in BODY."
    (mapc
     (lambda (pair)
       (setq body
  	   (replace-regexp-in-string
  	    (format "\$%s" (car pair))  ;FIXME: "\$" == "$"!
  	    (let ((val (cdr pair)))
                (if (listp val)
                    (let ((data-file (org-babel-temp-file "sql-data-")))
                      (with-temp-file data-file
                        (insert (orgtbl-to-csv
                                 val '(:fmt (lambda (el) (if (stringp el)
                                                        el
                                                      (format "%S" el)))))))
                      data-file)
                  (if (stringp val) val (format "%S" val))))
  	    body)))
     vars)
    body)
  
  (defun org-babel-prep-session:sql (session params)
    "Raise an error because Sql sessions aren't implemented."
    (error "SQL sessions not yet implemented"))
  
  (provide 'ob-sql)
  
  
  
  ;;; ob-sql.el ends here
  