Add some transform utilities to be made available in the command language.

package.lisp

@@ -31,6 +31,9 @@
 	   #:report-pgtable-stats
 	   #:report-pgstate-stats))
 
+(defpackage #:pgloader.transforms
+  (:use #:cl))
+
 (defpackage #:pgloader.parser
   (:use #:cl #:esrap #:pgloader.params)
   (:export #:parse-load))

transforms.lisp

@@ -0,0 +1,45 @@
+;;;
+;;; Tools to handle data conversion to PostgreSQL format
+;;;
+;;; Any function that you want to use to transform data with will get looked
+;;; up in the pgloader.transforms package, when using the default USING
+;;; syntax for transformations.
+
+(in-package :pgloader.transforms)
+
+(defun nil-to-cl-postgres-null (value)
+  "cl-mysql returns nil for NULL and cl-postgres wants :NULL"
+  (if (null value) :NULL value))
+
+(defun zero-dates-to-null (date-string)
+  "MySQL accepts '0000-00-00' as a date, we want :null instead."
+  (cond
+    ((null date-string) nil)
+    ((string= date-string "") nil)
+    ((string= date-string "0000-00-00") nil)
+    ((string= date-string "0000-00-00 00:00:00") nil)
+    (t date-string)))
+
+(defun date-with-no-separator
+    (date-string
+     &optional (format '((:year     0  4)
+			 (:month    4  6)
+			 (:day      6  8)
+			 (:hour     8 10)
+			 (:minute  10 12)
+			 (:seconds 12 14))))
+  "Apply this function when input date in like '20041002152952'"
+  ;; only process non-zero dates
+  (if (null (transform-zero-dates-to-null date-string)) nil
+      (destructuring-bind (&key year month day hour minute seconds
+				&allow-other-keys)
+	    (loop
+	       for (name start end) in format
+	       append (list name (subseq date-string start end)))
+	(format nil "~a-~a-~a ~a:~a:~a" year month day hour minute seconds))))
+
+(defun tinyint-to-boolean (integer-string)
+  "When using MySQL, strange things will happen, like encoding booleans into
+   tinyiny that are either 0 (false) or 1 (true). Of course PostgreSQL wants
+   'f' and 't', respectively."
+  (if (string= "0" integer-string) "f" "t"))