From 2145cded0efeb0eb141440d26c4bac624c66d7df Mon Sep 17 00:00:00 2001
From: Justin Kramer <jkkramer@gmail.com>
Date: Fri, 13 Jul 2012 18:45:25 -0400
Subject: [PATCH] format-predicate

---
 src/honeysql/core.clj   |  1 +
 src/honeysql/format.clj | 21 ++++++++++++++-------
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/src/honeysql/core.clj b/src/honeysql/core.clj
index 2bde710..fd33fc1 100644
--- a/src/honeysql/core.clj
+++ b/src/honeysql/core.clj
@@ -7,6 +7,7 @@
 (defalias call types/call)
 (defalias raw types/raw)
 (defalias format format/format)
+(defalias format-predicate format/format-predicate)
 
 (defn select [& fields]
   (let [[m fields] (if (map? (first fields))
diff --git a/src/honeysql/format.clj b/src/honeysql/format.clj
index a05945c..c870434 100644
--- a/src/honeysql/format.clj
+++ b/src/honeysql/format.clj
@@ -44,7 +44,7 @@
   "Determines the order that clauses will be placed within generated SQL"
   [:select :from :join :where :group-by :having :order-by :limit :offset])
 
-(declare to-sql)
+(declare to-sql format-predicate*)
 
 (defn format [sql-map]
   (binding [*params* (atom [])]
@@ -53,6 +53,13 @@
         (into [sql-str] @*params*)
         [sql-str]))))
 
+(defn format-predicate [pred]
+  (binding [*params* (atom [])]
+    (let [sql-str (format-predicate* pred)]
+      (if (seq @*params*)
+        (into [sql-str] @*params*)
+        [sql-str]))))
+
 (defprotocol ToSql
   (-to-sql [x]))
 
@@ -112,17 +119,17 @@
 
 ;;;;
 
-(defn format-predicate [pred]
+(defn format-predicate* [pred]
   (if-not (sequential? pred)
     (to-sql pred)
     (let [[op & args] pred
           op-name (name op)]
       (if (= "not" op-name)
-        (str "NOT " (format-predicate (first args)))
+        (str "NOT " (format-predicate* (first args)))
         (if (#{"and" "or" "xor"} op-name)
           (paren-wrap
            (string/join (str " " (string/upper-case op-name) " ")
-                        (map format-predicate args)))
+                        (map format-predicate* args)))
           (to-sql (apply call pred)))))))
 
 (defmulti format-clause
@@ -141,13 +148,13 @@
   (str "FROM " (comma-join (map to-sql tables))))
 
 (defmethod format-clause :where [[_ pred] _]
-  (str "WHERE " (format-predicate pred)))
+  (str "WHERE " (format-predicate* pred)))
 
 (defn format-join [table pred & [type]]
   (str (when type
          (str (string/upper-case (name type)) " "))
        "JOIN " (to-sql table)
-       " ON " (format-predicate pred)))
+       " ON " (format-predicate* pred)))
 
 (defmethod format-clause :join [[_ join-groups] _]
   (space-join (map #(apply format-join %) join-groups)))
@@ -156,7 +163,7 @@
   (str "GROUP BY " (comma-join (map to-sql fields))))
 
 (defmethod format-clause :having [[_ pred] _]
-  (str "HAVING " (format-predicate pred)))
+  (str "HAVING " (format-predicate* pred)))
 
 (defmethod format-clause :order-by [[_ fields] _]
   (str "ORDER BY "