From f08a4da60aad13cf99314223d86f86bb719709bc Mon Sep 17 00:00:00 2001
From: Jeremy Woertink <jeremywoertink@gmail.com>
Date: Mon, 17 Feb 2020 13:04:23 -0800
Subject: [PATCH] Add NoResultsError (#121)

---
 spec/statement_spec.cr | 9 +++++++++
 src/db/error.cr        | 4 ++++
 src/db/statement.cr    | 2 +-
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/spec/statement_spec.cr b/spec/statement_spec.cr
index f70937e..bf63f80 100644
--- a/spec/statement_spec.cr
+++ b/spec/statement_spec.cr
@@ -208,4 +208,13 @@ describe DB::Statement do
       db.pool.is_available?(DummyDriver::DummyConnection.connections.first)
     end
   end
+
+  it "raises NoResultsError for scalar" do
+    with_dummy_connection do |cnn|
+      stmt = cnn.prepared ""
+      expect_raises DB::NoResultsError do
+        stmt.scalar "SELECT LIMIT 0"
+      end
+    end
+  end
 end
diff --git a/src/db/error.cr b/src/db/error.cr
index c8a81f2..a304310 100644
--- a/src/db/error.cr
+++ b/src/db/error.cr
@@ -29,4 +29,8 @@ module DB
 
   class Rollback < Error
   end
+
+  # Raised when a scalar query returns no results.
+  class NoResultsError < Error
+  end
 end
diff --git a/src/db/statement.cr b/src/db/statement.cr
index 5c3f5e3..807b42a 100644
--- a/src/db/statement.cr
+++ b/src/db/statement.cr
@@ -15,7 +15,7 @@ module DB
         end
       end
 
-      raise "no results"
+      raise NoResultsError.new("no results")
     end
 
     # See `QueryMethods#query`