From f5ddaeed932777ec1e5636c1222881ba358728ca Mon Sep 17 00:00:00 2001
From: James Ryan Carr <rcarr@texeltek.com>
Date: Fri, 22 Nov 2013 11:35:36 -0500
Subject: [PATCH] Added fetch-size and max-rows functions.

---
 src/korma/core.clj       | 20 ++++++++++++++++++++
 src/korma/db.clj         | 10 +++++++---
 test/korma/test/core.clj |  8 ++++++++
 3 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/src/korma/core.clj b/src/korma/core.clj
index a4bc8f2..d5ceaca 100644
--- a/src/korma/core.clj
+++ b/src/korma/core.clj
@@ -395,6 +395,26 @@
   [s]
   (utils/generated s))
 
+(defn fetch-size
+  "Sets the JDBC fetch size for this query, i.e. the number of rows pulled back
+  with each round trip to the server. Fetch size defaults to 10 on most drivers.
+  This option will not affect which rows are returned, but if you are running
+  big queries then turning fetch size up (e.g. to 1000) can make them finish much faster.
+
+  (select users
+    (fetch-size 1000))"
+  [query fs]
+  (assoc-in query [:jdbc-options :fetch-size] fs))
+
+(defn max-rows
+  "Sets the JDBC max rows option. Useful as an alternative to (limit) for DBMSs that do
+  not support LIMIT (e.g. Oracle).
+
+  (select users
+    (max-rows 10))"
+  [query mr]
+  (assoc-in query [:jdbc-options :max-rows] mr))
+
 ;;*****************************************************
 ;; Query exec
 ;;*****************************************************
diff --git a/src/korma/db.clj b/src/korma/db.clj
index 49ea6aa..e7728d1 100644
--- a/src/korma/db.clj
+++ b/src/korma/db.clj
@@ -210,11 +210,15 @@
       (jdbc/print-sql-exception e)))
   (throw e))
 
-(defn- exec-sql [{:keys [results sql-str params]}]
+(defn- exec-sql [{:keys [results sql-str params jdbc-options]}]
   (try
     (case results
-      :results (jdbc/with-query-results rs (apply vector sql-str params)
-                 (vec rs))
+      :results (jdbc/with-query-results
+                  rs
+                  (if jdbc-options
+                    (apply vector jdbc-options sql-str params)
+                    (apply vector sql-str params))
+                  (vec rs))
       :keys (jdbc/do-prepared-return-keys sql-str params)
       (jdbc/do-prepared sql-str params))
     (catch Exception e
diff --git a/test/korma/test/core.clj b/test/korma/test/core.clj
index 2ae0262..0446fa8 100644
--- a/test/korma/test/core.clj
+++ b/test/korma/test/core.clj
@@ -305,6 +305,14 @@
            (select user2))))
   (set-delimiters "\""))
 
+(deftest jdbc-options
+  (is (= {:fetch-size 1000}
+         (:jdbc-options (query-only (select users (fetch-size 1000))))))
+  (is (= {:max-rows 10}
+         (:jdbc-options (query-only (select users (max-rows 10))))))
+  (is (= {:fetch-size 1 :max-rows 2}
+         (:jdbc-options (query-only (select users (fetch-size 1) (max-rows 2)))))))
+
 (deftest naming-delim-options
   (sql-only
     (is (= "SELECT DELIMS.* FROM DELIMS"