(defvar my-databases nil "A list of database names used by my-update-database.")
(setq my-databases '("square_training"))

;; Sends the current file to a chosen database
(defun my-update-database ()
  "Sends the current file to a chosen database."
  (interactive)
  (if (not my-sql-profile)
      (my-sql-set-profile))
  (let ((db_name (let ((completion-ignore-case t))
                   (ido-completing-read "Database: " my-databases))))
    (if (not (member db_name my-databases))
        (push db_name my-databases))
    (if buffer-file-name
        (progn
          (shell-command (concat "mysql " db_name " --host=" sql-server
                                 " --user=" sql-user " --password=" sql-password
                                 " < " buffer-file-name)))
    (message "No file associated with buffer."))))

(add-hook 'sql-mode-hook (lambda () (local-set-key (kbd "C-c C-b") 'my-update-database)))

;; The current mysql profile
(defvar my-sql-profile nil)

;; Links mysql profile names to sql-mode variables
(defvar my-sql-vars '(("localhost" . ("username" "password" "host"))
                      ("otherhost" . ("username" "password" "host"))))

(defun my-sql-mysql (change)
  (interactive "P")
  (my-sql-set-profile change)
  (sql-mysql))

;; Runs sql-mysql. When called with a prefix argument (or on first run) it
;; prompts for the sql profile to select.
(defun my-sql-set-profile (&optional change)
  "Sets up the sql-mode variables and then runs sql-mysql."
  (if (or (not my-sql-profile) change)
      (let ((completion-ignore-case t)
            (completion-function 'ido-completing-read))
        (let ((choice (funcall completion-function "SQL Profile: " my-sql-vars)))
          (dolist (profile my-sql-vars)
            (let ((profile-name (car profile))
                  (profile-vars (cdr profile)))
              (if (string-match profile-name choice)
                  (setq sql-user (nth 0 profile-vars)
                        sql-password (nth 1 profile-vars)
                        sql-server (nth 2 profile-vars)
                        my-sql-profile profile-name))))))))

(provide 'my-mysql)