change `(update widgets ...)' to `(update (table widgets) ...)' so as to not have a single symbol floating around there in order to make update statements composable

ssql.scm

@@ -116,6 +116,9 @@
                                      values)
                                 ", ")))
 
+               ((table (table))
+                (symbol->string table))
+
                ((insert into rest)
                 (sprintf "INSERT INTO ~A ~A"
                          into

tests/ansi-test.scm

@@ -30,11 +30,11 @@
 (test-group "updates"
   (test "simple case"
     "UPDATE actors SET firstname = 'Rube', lastname = 'Goldberg'"
-    (ssql->sql #f '(update actors (set (firstname "Rube") (lastname "Goldberg")))))
+    (ssql->sql #f '(update (table actors) (set (firstname "Rube") (lastname "Goldberg")))))
 
   (test "with condition"
     "UPDATE actors SET firstname = 'Felix' WHERE (lastname = 'Winkelmann')"
-    (ssql->sql #f '(update actors (set (firstname "Felix")) (where (= lastname "Winkelmann"))))))
+    (ssql->sql #f '(update (table actors) (set (firstname "Felix")) (where (= lastname "Winkelmann"))))))
 
 (test-group "inserts"
   (test "with sub-queries"