From fbd8c0bfbb8f642fc00cecd7429b37b8517750c0 Mon Sep 17 00:00:00 2001
From: Richard Newman <rnewman@twinql.com>
Date: Wed, 20 Jul 2016 14:25:24 -0700
Subject: [PATCH] Always SELECT DISTINCT.

---
 src/datomish/query.cljc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/datomish/query.cljc b/src/datomish/query.cljc
index c0e0ba81..23adcbca 100644
--- a/src/datomish/query.cljc
+++ b/src/datomish/query.cljc
@@ -23,7 +23,12 @@
 
 (defn context->sql-clause [context]
   (merge
-    {:select (projection/sql-projection context)}
+    {:select (projection/sql-projection context)
+
+     ;; Always SELECT DISTINCT, because Datalog is set-based.
+     ;; TODO: determine from schema analysis whether we can avoid
+     ;; the need to do this.
+     :modifiers [:distinct]}
     (clauses/cc->partial-subquery (:cc context))))
 
 (defn context->sql-string [context]