Fix toWeek monotonicity

src/Functions/CustomWeekTransforms.h

@@ -4,6 +4,7 @@
 #include <Columns/ColumnsNumber.h>
 #include <common/types.h>
 #include <Core/DecimalFunctions.h>
+#include <Functions/DateTimeTransforms.h>
 #include <Functions/FunctionHelpers.h>
 #include <Functions/extractTimeZoneFromFunctionArguments.h>
 #include <Functions/IFunction.h>
@@ -26,43 +27,6 @@ namespace ErrorCodes
  * CustomWeek Transformations.
   */
 
-static inline UInt32 dateIsNotSupported(const char * name)
-{
-    throw Exception("Illegal type Date of argument for function " + std::string(name), ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
-}
-
-/// This factor transformation will say that the function is monotone everywhere.
-struct ZeroTransform
-{
-    static inline UInt16 execute(UInt16, UInt8, const DateLUTImpl &) { return 0; }
-    static inline UInt16 execute(UInt32, UInt8, const DateLUTImpl &) { return 0; }
-    static inline UInt16 execute(Int64, UInt8, const DateLUTImpl &) { return 0; }
-};
-
-struct ToWeekImpl
-{
-    static constexpr auto name = "toWeek";
-
-    static inline UInt8 execute(Int64 t, UInt8 week_mode, const DateLUTImpl & time_zone)
-    {
-        // TODO: ditch conversion to DayNum, since it doesn't support extended range.
-        YearWeek yw = time_zone.toYearWeek(time_zone.toDayNum(t), week_mode);
-        return yw.second;
-    }
-    static inline UInt8 execute(UInt32 t, UInt8 week_mode, const DateLUTImpl & time_zone)
-    {
-        YearWeek yw = time_zone.toYearWeek(time_zone.toDayNum(t), week_mode);
-        return yw.second;
-    }
-    static inline UInt8 execute(UInt16 d, UInt8 week_mode, const DateLUTImpl & time_zone)
-    {
-        YearWeek yw = time_zone.toYearWeek(DayNum(d), week_mode);
-        return yw.second;
-    }
-
-    using FactorTransform = ZeroTransform;
-};
-
 struct ToYearWeekImpl
 {
     static constexpr auto name = "toYearWeek";
@@ -110,10 +74,34 @@ struct ToStartOfWeekImpl
     using FactorTransform = ZeroTransform;
 };
 
-template <typename FromType, typename ToType, typename Transform>
+struct ToWeekImpl
-struct Transformer
 {
-    explicit Transformer(Transform transform_)
+    static constexpr auto name = "toWeek";
+
+    static inline UInt8 execute(Int64 t, UInt8 week_mode, const DateLUTImpl & time_zone)
+    {
+        // TODO: ditch conversion to DayNum, since it doesn't support extended range.
+        YearWeek yw = time_zone.toYearWeek(time_zone.toDayNum(t), week_mode);
+        return yw.second;
+    }
+    static inline UInt8 execute(UInt32 t, UInt8 week_mode, const DateLUTImpl & time_zone)
+    {
+        YearWeek yw = time_zone.toYearWeek(time_zone.toDayNum(t), week_mode);
+        return yw.second;
+    }
+    static inline UInt8 execute(UInt16 d, UInt8 week_mode, const DateLUTImpl & time_zone)
+    {
+        YearWeek yw = time_zone.toYearWeek(DayNum(d), week_mode);
+        return yw.second;
+    }
+
+    using FactorTransform = ToStartOfYearImpl;
+};
+
+template <typename FromType, typename ToType, typename Transform>
+struct WeekTransformer
+{
+    explicit WeekTransformer(Transform transform_)
         : transform(std::move(transform_))
     {}
 
@@ -139,7 +127,7 @@ struct CustomWeekTransformImpl
     template <typename Transform>
     static ColumnPtr execute(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t /*input_rows_count*/, Transform transform = {})
     {
-        const auto op = Transformer<typename FromDataType::FieldType, typename ToDataType::FieldType, Transform>{std::move(transform)};
+        const auto op = WeekTransformer<typename FromDataType::FieldType, typename ToDataType::FieldType, Transform>{std::move(transform)};
 
         UInt8 week_mode = DEFAULT_WEEK_MODE;
         if (arguments.size() > 1)

src/Functions/FunctionCustomWeekToSomething.h

@@ -10,9 +10,9 @@
 
 namespace DB
 {
+
 namespace ErrorCodes
 {
-    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
     extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
 }
 
@@ -143,15 +143,15 @@ public:
 
         if (checkAndGetDataType<DataTypeDate>(&type))
         {
-            return Transform::FactorTransform::execute(UInt16(left.get<UInt64>()), DEFAULT_WEEK_MODE, date_lut)
+            return Transform::FactorTransform::execute(UInt16(left.get<UInt64>()), date_lut)
-                    == Transform::FactorTransform::execute(UInt16(right.get<UInt64>()), DEFAULT_WEEK_MODE, date_lut)
+                    == Transform::FactorTransform::execute(UInt16(right.get<UInt64>()), date_lut)
                 ? is_monotonic
                 : is_not_monotonic;
         }
         else
         {
-            return Transform::FactorTransform::execute(UInt32(left.get<UInt64>()), DEFAULT_WEEK_MODE, date_lut)
+            return Transform::FactorTransform::execute(UInt32(left.get<UInt64>()), date_lut)
-                    == Transform::FactorTransform::execute(UInt32(right.get<UInt64>()), DEFAULT_WEEK_MODE, date_lut)
+                    == Transform::FactorTransform::execute(UInt32(right.get<UInt64>()), date_lut)
                 ? is_monotonic
                 : is_not_monotonic;
         }

tests/queries/0_stateless/01881_to_week_monotonic_fix.reference

@@ -0,0 +1,4 @@
+1	2020-11-11
+1	2021-01-01
+1	2020-11-11
+1	2021-01-01

tests/queries/0_stateless/01881_to_week_monotonic_fix.sql

@@ -0,0 +1,11 @@
+drop table if exists test_tbl;
+
+create table test_tbl (vend_nm String, ship_dt Date) engine MergeTree partition by toWeek(ship_dt) order by vend_nm;
+
+insert into test_tbl values('1', '2020-11-11'), ('1', '2021-01-01');
+
+select * From test_tbl where ship_dt >= toDate('2020-11-01') and ship_dt <= toDate('2021-05-05') order by ship_dt;
+
+select * From test_tbl where ship_dt >= toDate('2020-01-01') and ship_dt <= toDate('2021-05-05') order by ship_dt;
+
+drop table test_tbl;