Add support for MS SQL smalldatatime data type.

Availability of a test case for MS SQL allows to make progress on this
limitation and add support to the smalldatetime data type. It is
converted server-side with the same CONVERT expression as the longer
datetime datatype.

Fixes #431.

src/monkey/mssql.lisp

@@ -94,7 +94,7 @@
              (:syb-int4 (unsigned-to-signed (mem-ref data :unsigned-int) 4))
              (:syb-int8 (mem-ref data :int8))
              (:syb-flt8 (mem-ref data :double))
-             (:syb-datetime
+             ((:syb-datetime :syb-datetime4)
               (with-foreign-pointer (%buf +numeric-buf-sz+)
                 (let ((count
                        (%dbconvert %dbproc

src/sources/mssql/mssql-cast-rules.lisp

@@ -59,6 +59,7 @@
     (:source (:type "varbinary") :target (:type "bytea")
              :using pgloader.transforms::byte-vector-to-bytea)
 
+    (:source (:type "smalldatetime") :target (:type "timestamptz"))
     (:source (:type "datetime") :target (:type "timestamptz"))
     (:source (:type "datetime2") :target (:type "timestamptz")))
   "Data Type Casting to migrate from MSSQL to PostgreSQL")

src/sources/mssql/mssql-schema.lisp

@@ -283,6 +283,7 @@ ORDER BY KCU1.CONSTRAINT_NAME, KCU1.ORDINAL_POSITION"
    Mostly we just use the name, and make try to avoid parsing dates."
   (case (intern (string-upcase type) "KEYWORD")
     (:datetime       (format nil "convert(varchar, [~a], 126)" name))
+    (:smalldatetime  (format nil "convert(varchar, [~a], 126)" name))
     (:bigint         (format nil "cast([~a] as numeric)" name))
     (t               (format nil "[~a]" name))))