add support for RETURNING

ssql-postgresql.scm

@@ -22,6 +22,7 @@
 (define-operators *postgresql-translator*
   (limit prefix)
   (offset prefix)
+  (returning prefix "RETURNING" ", ")
   (random function))
 
 (register-sql-engine! connection? *postgresql-translator*)

tests/run.scm

@@ -6,7 +6,7 @@
 (define *test-postgresql-translator* 
   (derive-object (*postgresql-translator* self super)
                  ((escape-string string)
-                  (super (ssql-connection) string))))
+                  (string-translate* string '(("'" . "''"))))))
 
 (register-sql-engine! (lambda (x) (eq? x #t)) *test-postgresql-translator*)
 
@@ -23,6 +23,10 @@
 
   (test "random()"
     "SELECT * FROM widgets ORDER BY RANDOM()"
-    (ssql->sql #t `(select (columns *) (from widgets) (order (random))))))
+    (ssql->sql #t `(select (columns *) (from widgets) (order (random)))))
+
+  (test "returning"
+    "INSERT INTO widgets VALUES ('foo', 'bar') RETURNING id, name"
+    (ssql->sql #t '(insert (into widgets) (values ("foo" "bar")) (returning id name)))))
 
 (test-exit)