From 71d0682a2b32621d5c317072c2b1c96230900fec Mon Sep 17 00:00:00 2001
From: vdimir <vdimir@yandex-team.ru>
Date: Thu, 8 Jul 2021 12:24:08 +0300
Subject: [PATCH] Use FieldVisitor to compare offsets in
 WindowFrame::checkValid

---
 src/Common/FieldVisitorsAccurateComparison.h | 12 ++++++++++++
 src/Interpreters/WindowDescription.cpp       |  6 ++++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/Common/FieldVisitorsAccurateComparison.h b/src/Common/FieldVisitorsAccurateComparison.h
index 0f605b7da23..ba3fabd1535 100644
--- a/src/Common/FieldVisitorsAccurateComparison.h
+++ b/src/Common/FieldVisitorsAccurateComparison.h
@@ -117,4 +117,16 @@ public:
     }
 };
 
+
+class FieldVisitorAccurateLessOrEqual : public StaticVisitor<bool>
+{
+public:
+    template <typename T, typename U>
+    bool operator()(const T & l, const U & r) const
+    {
+        auto less_cmp = FieldVisitorAccurateLess();
+        return !less_cmp(r, l);
+    }
+};
+
 }
diff --git a/src/Interpreters/WindowDescription.cpp b/src/Interpreters/WindowDescription.cpp
index 4de15af820f..923e10ed31b 100644
--- a/src/Interpreters/WindowDescription.cpp
+++ b/src/Interpreters/WindowDescription.cpp
@@ -1,6 +1,7 @@
 #include <Interpreters/WindowDescription.h>
 
 #include <Core/Field.h>
+#include <Common/FieldVisitorsAccurateComparison.h>
 #include <Common/FieldVisitorToString.h>
 #include <IO/Operators.h>
 #include <Parsers/ASTFunction.h>
@@ -160,7 +161,8 @@ void WindowFrame::checkValid() const
         bool begin_less_equal_end;
         if (begin_preceding && end_preceding)
         {
-            begin_less_equal_end = begin_offset.get<Int64>() >= end_offset.get<Int64>();
+            /// we can't compare Fields using operator<= if fields have different types
+            begin_less_equal_end = applyVisitor(FieldVisitorAccurateLessOrEqual(), end_offset, begin_offset);
         }
         else if (begin_preceding && !end_preceding)
         {
@@ -172,7 +174,7 @@ void WindowFrame::checkValid() const
         }
         else /* if (!begin_preceding && !end_preceding) */
         {
-            begin_less_equal_end = begin_offset.get<Int64>() <= end_offset.get<Int64>();
+            begin_less_equal_end = applyVisitor(FieldVisitorAccurateLessOrEqual(), begin_offset, end_offset);
         }
 
         if (!begin_less_equal_end)