1 files changed, 8 insertions, 0 deletions
diff --git a/lib/top.ur b/lib/top.ur
index 0bc345de..d36af3f3 100644
--- a/lib/top.ur
+++ b/lib/top.ur
@@ -157,3 +157,11 @@ fun oneOrNoRows (tables ::: {{Type}}) (exps ::: {Type})
     query q
           (fn fs _ => return (Some fs))
           None
+
+fun oneRow (tables ::: {{Type}}) (exps ::: {Type})
+                (q : sql_query tables exps) [tables ~ exps] =
+    o <- oneOrNoRows q;
+    return (case o of
+                None => error <xml>Query returned no rows</xml>
+              | Some r => r)
+