From f217e86038650835c0bf69bc25e903457ccb92d4 Mon Sep 17 00:00:00 2001
From: Sean Corfield <sean@corfield.org>
Date: Mon, 1 Apr 2019 22:19:02 -0700
Subject: [PATCH] Address #2 by adding rs/as-arrays

---
 src/next/jdbc/result_set.clj | 26 +++++++++++++++++++++++++-
 test/next/jdbc_test.clj      |  4 +++-
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/next/jdbc/result_set.clj b/src/next/jdbc/result_set.clj
index 6f23d1f..2a7eb80 100644
--- a/src/next/jdbc/result_set.clj
+++ b/src/next/jdbc/result_set.clj
@@ -31,6 +31,10 @@
                        (.getColumnLabel rsmeta i)))
             idxs))))
 
+(defprotocol ColumnarResultSet
+  (column-names [this])
+  (row-values [this]))
+
 (defn- mapify-result-set
   "Given a result set, return an object that wraps the current row as a hash
   map. Note that a result set is mutable and the current row will change behind
@@ -76,7 +80,27 @@
            (seq (mapv (fn [^Integer i]
                         (clojure.lang.MapEntry. (nth @cols (dec i))
                                                 (.getObject rs i)))
-                      (range 1 (inc (count @cols)))))))))
+                      (range 1 (inc (count @cols))))))
+
+      ColumnarResultSet
+      (column-names [this] @cols)
+      (row-values [this]
+                  (mapv (fn [^Integer i] (.getObject rs i))
+                        (range 1 (inc (count @cols))))))))
+
+(defn as-arrays
+  "A reducing function that can be used on a result set to produce an
+  array-based representation, where the first element is a vector of the
+  column names in the result set, and subsequent elements are vectors of
+  the rows from the result set.
+
+  It should be used with a nil initial value:
+
+  (reduce rs/as-arrays nil (reducible! con sql-params))"
+  [result rs-map]
+  (if result
+    (conj result (row-values rs-map))
+    (conj [(column-names rs-map)] (row-values rs-map))))
 
 (defn- reduce-stmt
   "Execute the PreparedStatement, attempt to get either its ResultSet or
diff --git a/test/next/jdbc_test.clj b/test/next/jdbc_test.clj
index 8183c77..88e16b3 100644
--- a/test/next/jdbc_test.clj
+++ b/test/next/jdbc_test.clj
@@ -149,4 +149,6 @@
   (execute! con ["select * from fruit where name = ?" "Pear"])
 
   (delete! con :fruit {:id 1})
-  (update! con :fruit {:appearance "Brown"} {:name "Banana"}))
+  (update! con :fruit {:appearance "Brown"} {:name "Banana"})
+
+  (reduce rs/as-arrays nil (reducible! con ["select * from fruit"])))