Merge pull request #201 from vincent-dm/master

adds support for JOIN ... USING (...) syntax (#188)

src/honeysql/format.cljc

@@ -489,10 +489,13 @@
   (str "WHERE " (format-predicate* pred)))
 
 (defn format-join [type table pred]
-  (cond-> (str (when type
-                 (str (string/upper-case (name type)) " "))
-               "JOIN " (to-sql table))
-    pred (str " ON " (format-predicate* pred))))
+  (str (when type
+         (str (string/upper-case (name type)) " "))
+       "JOIN " (to-sql table)
+       (when pred
+         (if (= :using (first pred))
+           (str " USING (" (->> pred rest (map quote-identifier) comma-join) ")")
+           (str " ON " (format-predicate* pred))))))
 
 (defmethod format-clause :join [[_ join-groups] _]
   (space-join (map #(apply format-join :inner %)

test/honeysql/core_test.cljc

@@ -192,6 +192,14 @@
                (join :x [:= :foo.id :x.id] :y nil)
                sql/format)))))
 
+(deftest join-using-test
+  (testing "nil join"
+    (is (= ["SELECT * FROM foo INNER JOIN x USING (id) INNER JOIN y USING (foo, bar)"]
+           (-> (select :*)
+               (from :foo)
+               (join :x [:using :id] :y [:using :foo :bar])
+               sql/format)))))
+
 (deftest inline-test
   (is (= ["SELECT * FROM foo WHERE id = 5"]
          (-> (select :*)