mysql.ss
#lang scheme/base
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; DBD-JAZMYSQL.plt
;;
;; DBD Wrapper over jaz/mysql.
;;
;; Bonzai Lab, LLC.  All rights reserved.
;;
;; released under LGPL.
;;
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; mysql.ss - the main driver/wrapper over jaz/mysql.
;; yc 9/10/2009 - first version
(require (planet bzlib/base)
         (planet bzlib/dbi)
         (prefix-in dbd: (planet jaz/mysql)))

(define (mysql-connect driver . attrs)
  (let-values (((loader attrs)
                (filter-file-loader/attrs attrs)))
    (let ((handle (make-handle driver (apply* dbd:connect attrs)
                               (make-immutable-hash-registry)
                               0)))
      (load-files! handle (if (list? loader) loader
                              (list loader)))
      handle)))

(define (mysql-disconnect handle)
  (dbd:close-connection! (handle-conn handle)))

(define (mysql-query handle stmt (args '()))
  (convert-result
   (if (symbol? stmt) ;; check to see if it exists....
       (if-it (registry-ref (handle-query handle) stmt) ;; yes it exists!!!...
              (begin
                (let ((query (prepared-query it)) 
                      (stmt (prepared-inner it)))
                  (dbd:execute stmt (map cell->sql-cell (phq-map-values query args)))))
              (error 'query "unknown prepared statement ~a" stmt))
       (let ((query (make-place-holder-query default-converter stmt)))
         (dbd:query #:connection (handle-conn handle) 
                    (phq-merge-query query
                                     (map cell->sql-cell (phq-map-values query args))))))))

(define (mysql-prepare dbh key stmt)
  (define (helper query)
    (registry-set! (handle-query dbh)
                   key
                   (make-prepared query
                                  (dbd:prepare #:connection 
                                               (handle-conn dbh) 
                                               (phq-converted query)))))
  (helper (make-place-holder-query question-converter stmt)))

(define (convert-result rs)
  (cond ((dbd:side-effect? rs)
         rs)
        ((dbd:result-set? rs) 
         (cons (vector->list (dbd:result-set-field-names rs))
               (map vector->list (dbd:result-set-rows rs))))))

(define (cell->sql-cell cell)
  (cond ((null? cell) dbd:sql-null)
        (else cell)))

(define (sql-cell->cell cell)
  (cond ((dbd:sql-null? cell) '())
        (else cell)))

(registry-set! drivers 'jazmysql
               (make-driver mysql-connect
                            mysql-disconnect
                            mysql-query
                            mysql-prepare
                            default-begin
                            default-commit
                            default-rollback))