From 36fc6432ce2194cdf3ba789a2f2ef1b0d41b9658 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=87=E5=BA=B7?= <mingge@xiaohongshu.com>
Date: Tue, 11 May 2021 21:03:32 +0800
Subject: [PATCH] support for order by fill with DateTime64

---
 src/Processors/Transforms/FillingTransform.cpp    | 15 ++++++++++++++-
 .../01868_order_by_fill_with_datetime64.reference | 14 ++++++++++++++
 .../01868_order_by_fill_with_datetime64.sql       |  2 ++
 3 files changed, 30 insertions(+), 1 deletion(-)
 create mode 100644 tests/queries/0_stateless/01868_order_by_fill_with_datetime64.reference
 create mode 100644 tests/queries/0_stateless/01868_order_by_fill_with_datetime64.sql

diff --git a/src/Processors/Transforms/FillingTransform.cpp b/src/Processors/Transforms/FillingTransform.cpp
index 317453f272a..46b913aed7a 100644
--- a/src/Processors/Transforms/FillingTransform.cpp
+++ b/src/Processors/Transforms/FillingTransform.cpp
@@ -1,6 +1,11 @@
 #include <Processors/Transforms/FillingTransform.h>
 #include <Interpreters/convertFieldToType.h>
 #include <DataTypes/DataTypesNumber.h>
+#include <DataTypes/DataTypeDateTime64.h>
+#include <DataTypes/IDataType.h>
+#include <Core/Types.h>
+#include <DataTypes/DataTypesDecimal.h>
+
 
 namespace DB
 {
@@ -38,11 +43,19 @@ FillingTransform::FillingTransform(
         DataTypePtr to_type;
 
         /// TODO Wrong results for big integers.
-        if (isInteger(type) || which.isDateOrDateTime())
+        if (isInteger(type) || which.isDate() || which.isDateTime())
         {
             max_type = Field::Types::Int64;
             to_type = std::make_shared<DataTypeInt64>();
         }
+        else if (which.isDateTime64())
+        {
+            max_type = Field::Types::Decimal64;
+            const auto & dateType = static_cast<const DataTypeDateTime64 &>(*type);
+            size_t precision = dateType.getPrecision();
+            size_t scale = dateType.getScale();
+            to_type = std::make_shared<DataTypeDecimal<Decimal64>>(precision, scale);
+        }
         else if (which.isFloat())
         {
             max_type = Field::Types::Float64;
diff --git a/tests/queries/0_stateless/01868_order_by_fill_with_datetime64.reference b/tests/queries/0_stateless/01868_order_by_fill_with_datetime64.reference
new file mode 100644
index 00000000000..420ff36feb4
--- /dev/null
+++ b/tests/queries/0_stateless/01868_order_by_fill_with_datetime64.reference
@@ -0,0 +1,14 @@
+1970-01-01 08:16:40.000	original
+1970-01-01 08:33:20.000	
+1970-01-01 08:50:00.000	
+1970-01-01 09:06:40.000	original
+1970-01-01 09:23:20.000	
+1970-01-01 09:40:00.000	
+1970-01-01 09:56:40.000	original
+1970-01-01 08:16:40.000000000	original
+1970-01-01 08:33:20.000000000	
+1970-01-01 08:50:00.000000000	
+1970-01-01 09:06:40.000000000	original
+1970-01-01 09:23:20.000000000	
+1970-01-01 09:40:00.000000000	
+1970-01-01 09:56:40.000000000	original
diff --git a/tests/queries/0_stateless/01868_order_by_fill_with_datetime64.sql b/tests/queries/0_stateless/01868_order_by_fill_with_datetime64.sql
new file mode 100644
index 00000000000..5425de8f3ee
--- /dev/null
+++ b/tests/queries/0_stateless/01868_order_by_fill_with_datetime64.sql
@@ -0,0 +1,2 @@
+SELECT n, source FROM (SELECT  toDateTime64(number * 1000, 3) AS n, 'original' AS source  FROM numbers(10)  WHERE (number % 3) = 1 ) ORDER BY n ASC WITH FILL STEP toDateTime64(1000, 3);
+SELECT n, source FROM (SELECT  toDateTime64(number * 1000, 9) AS n, 'original' AS source  FROM numbers(10)  WHERE (number % 3) = 1 ) ORDER BY n ASC WITH FILL STEP toDateTime64(1000, 9);