post-review changes

src/DataTypes/Serializations/ISerialization.h

@@ -17,6 +17,7 @@ namespace DB
 namespace ErrorCodes
 {
     extern const int LOGICAL_ERROR;
+    extern const int NOT_IMPLEMENTED;
 }
 
 class IDataType;

src/DataTypes/Serializations/SerializationAsStringNonTrivialJSON.h

@@ -12,6 +12,11 @@
 namespace DB
 {
 
+namespace ErrorCodes
+{
+    extern const int NOT_IMPLEMENTED;
+}
+
 /** Serialization for non-numeric non-string data types serialized as JSON strings
  * For these data types, we support an option, input_format_json_empty_as_default, which, when set to 1,
  * allows for JSON deserialization to treat an encountered empty string as a default value for the specified type.

src/DataTypes/Serializations/SerializationNullable.cpp

@@ -868,7 +868,7 @@ template <Strategy strategy>
 ReturnType<strategy> deserializeTextJSONImpl(IColumn & column, ReadBuffer & istr, const FormatSettings & settings, const SerializationPtr & nested, bool & is_null)
 {
     auto check_for_null = [](ReadBuffer & buf){ return checkStringByFirstCharacterAndAssertTheRest("null", buf); };
-    auto deserialize_nested = [&nested, &settings](IColumn & nested_column, ReadBuffer & buf)
+    auto deserialize_nested = [&nested, &settings](IColumn & nested_column, ReadBuffer & buf) -> ReturnType<strategy>
     {
         if constexpr (strategy == Strategy::TryDeserialize)
             return nested->tryDeserializeTextJSON(nested_column, buf, settings);

tests/queries/0_stateless/03203_json_empty_as_default.reference

@@ -1,20 +1,47 @@
+-- Simple types
+-- { echoOn }
+SELECT x FROM format(JSONEachRow, 'x Date', '{"x":""}');
 1970-01-01
+SELECT x FROM format(JSONEachRow, 'x Date32', '{"x":""}');
 1970-01-01
+SELECT toTimeZone(x, 'UTC') FROM format(JSONEachRow, 'x DateTime', '{"x":""}');
 1970-01-01 00:00:00
+SELECT toTimeZone(x, 'UTC') FROM format(JSONEachRow, 'x DateTime64', '{"x":""}');
 1970-01-01 00:00:00.000
+SELECT x FROM format(JSONEachRow, 'x IPv4', '{"x":""}');
 0.0.0.0
+SELECT x FROM format(JSONEachRow, 'x IPv6', '{"x":""}');
 ::
+SELECT x FROM format(JSONEachRow, 'x UUID', '{"x":""}');
 00000000-0000-0000-0000-000000000000
+-- { echoOn }
+SELECT COUNT(DISTINCT col) FROM table1;
 1
+-- { echoOn }
+SELECT * FROM table1 ORDER BY address ASC;
 ::
 2001:db8:3333:4444:5555:6666:7777:8888
+-- Nullable
+-- { echoOn }
+SELECT x FROM format(JSONEachRow, 'x Nullable(IPv6)', '{"x":""}');
 ::
+-- Compound types
+SELECT x FROM format(JSONEachRow, 'x Array(UUID)', '{"x":["00000000-0000-0000-0000-000000000000","b15f852c-c41a-4fd6-9247-1929c841715e",""]}');
 ['00000000-0000-0000-0000-000000000000','b15f852c-c41a-4fd6-9247-1929c841715e','00000000-0000-0000-0000-000000000000']
+SELECT x FROM format(JSONEachRow, 'x Array(Nullable(IPv6))', '{"x":["",""]}');
 ['::','::']
+SELECT x FROM format(JSONEachRow, 'x Tuple(Date, IPv4, String)', '{"x":["", "", "abc"]}');
 ('1970-01-01','0.0.0.0','abc')
+SELECT x FROM format(JSONEachRow, 'x Map(String, IPv6)', '{"x":{"abc": ""}}');
 {'abc':'::'}
+SELECT x FROM format(JSONEachRow, 'x Variant(Date, UUID)', '{"x":""}');
 00000000-0000-0000-0000-000000000000
+-- Deep composition
+SELECT x FROM format(JSONEachRow, 'x Array(Array(IPv6))', '{"x":[["2001:db8:3333:4444:CCCC:DDDD:EEEE:FFFF", ""], ["", "2001:db8:3333:4444:5555:6666:7777:8888"]]}');
 [['2001:db8:3333:4444:cccc:dddd:eeee:ffff','::'],['::','2001:db8:3333:4444:5555:6666:7777:8888']]
+SELECT x FROM format(JSONEachRow, 'x Variant(Date, Array(UUID))', '{"x":["", "b15f852c-c41a-4fd6-9247-1929c841715e"]}');
 ['00000000-0000-0000-0000-000000000000','b15f852c-c41a-4fd6-9247-1929c841715e']
+SELECT x FROM format(JSONEachRow, 'x Tuple(Array(UUID), Tuple(UUID, Map(String, IPv6)))', '{"x":[[""], ["",{"abc":""}]]}');
 (['00000000-0000-0000-0000-000000000000'],('00000000-0000-0000-0000-000000000000',{'abc':'::'}))
+SELECT x FROM format(JSONEachRow, 'x Map(Tuple(Date,IPv4), Variant(UUID,IPv6))', '{"x":{["",""]:""}}');
 {('1970-01-01','0.0.0.0'):'00000000-0000-0000-0000-000000000000'}

tests/queries/0_stateless/03203_json_empty_as_default.sql

@@ -1,7 +1,7 @@
-set input_format_json_empty_as_default = 1;
+SET input_format_json_empty_as_default = 1, allow_experimental_variant_type = 1;
-set allow_experimental_variant_type = 1;
 
-# Simple types
+-- Simple types
+-- { echoOn }
 SELECT x FROM format(JSONEachRow, 'x Date', '{"x":""}');
 SELECT x FROM format(JSONEachRow, 'x Date32', '{"x":""}');
 SELECT toTimeZone(x, 'UTC') FROM format(JSONEachRow, 'x DateTime', '{"x":""}');
@@ -9,8 +9,9 @@ SELECT toTimeZone(x, 'UTC') FROM format(JSONEachRow, 'x DateTime64', '{"x":""}')
 SELECT x FROM format(JSONEachRow, 'x IPv4', '{"x":""}');
 SELECT x FROM format(JSONEachRow, 'x IPv6', '{"x":""}');
 SELECT x FROM format(JSONEachRow, 'x UUID', '{"x":""}');
+-- { echoOff }
 
-# Simple type AggregateFunction
+-- Simple type AggregateFunction
 DROP TABLE IF EXISTS table1;
 CREATE TABLE table1(col AggregateFunction(uniq, UInt64)) ENGINE=Memory();
 DROP TABLE IF EXISTS table2;
@@ -18,35 +19,41 @@ CREATE TABLE table2(UserID UInt64) ENGINE=Memory();
 
 INSERT INTO table1 SELECT uniqState(UserID) FROM table2;
 INSERT INTO table1 SELECT x FROM format(JSONEachRow, 'x AggregateFunction(uniq, UInt64)' AS T, '{"x":""}');
+
+-- { echoOn }
 SELECT COUNT(DISTINCT col) FROM table1;
+-- { echoOff }
 
 DROP TABLE table1;
 DROP TABLE table2;
 
-# The setting input_format_defaults_for_omitted_fields determines the default value if enabled.
+-- The setting input_format_defaults_for_omitted_fields determines the default value if enabled.
 CREATE TABLE table1(address IPv6 DEFAULT toIPv6('2001:db8:3333:4444:5555:6666:7777:8888')) ENGINE=Memory();
 
-set input_format_defaults_for_omitted_fields = 0;
+SET input_format_defaults_for_omitted_fields = 0;
 INSERT INTO table1 FORMAT JSONEachRow {"address":""};
 
-set input_format_defaults_for_omitted_fields = 1;
+SET input_format_defaults_for_omitted_fields = 1;
 INSERT INTO table1 FORMAT JSONEachRow {"address":""};
 
+-- { echoOn }
 SELECT * FROM table1 ORDER BY address ASC;
+-- { echoOff }
 
 DROP TABLE table1;
 
-# Nullable
+-- Nullable
+-- { echoOn }
 SELECT x FROM format(JSONEachRow, 'x Nullable(IPv6)', '{"x":""}');
 
-# Compound types
+-- Compound types
 SELECT x FROM format(JSONEachRow, 'x Array(UUID)', '{"x":["00000000-0000-0000-0000-000000000000","b15f852c-c41a-4fd6-9247-1929c841715e",""]}');
 SELECT x FROM format(JSONEachRow, 'x Array(Nullable(IPv6))', '{"x":["",""]}');
 SELECT x FROM format(JSONEachRow, 'x Tuple(Date, IPv4, String)', '{"x":["", "", "abc"]}');
 SELECT x FROM format(JSONEachRow, 'x Map(String, IPv6)', '{"x":{"abc": ""}}');
 SELECT x FROM format(JSONEachRow, 'x Variant(Date, UUID)', '{"x":""}');
 
-# Deep composition
+-- Deep composition
 SELECT x FROM format(JSONEachRow, 'x Array(Array(IPv6))', '{"x":[["2001:db8:3333:4444:CCCC:DDDD:EEEE:FFFF", ""], ["", "2001:db8:3333:4444:5555:6666:7777:8888"]]}');
 SELECT x FROM format(JSONEachRow, 'x Variant(Date, Array(UUID))', '{"x":["", "b15f852c-c41a-4fd6-9247-1929c841715e"]}');
 SELECT x FROM format(JSONEachRow, 'x Tuple(Array(UUID), Tuple(UUID, Map(String, IPv6)))', '{"x":[[""], ["",{"abc":""}]]}');