Implement null_as_default for JSONStrings formats

src/DataTypes/DataTypeNullable.cpp

@@ -318,13 +318,20 @@ ReturnType DataTypeNullable::deserializeTextQuoted(IColumn & column, ReadBuffer
 
 void DataTypeNullable::deserializeWholeText(IColumn & column, ReadBuffer & istr, const FormatSettings & settings) const
 {
-    safeDeserialize(column, *nested_data_type,
+    deserializeWholeText<void>(column, istr, settings, nested_data_type);
+}
+
+template <typename ReturnType>
+ReturnType DataTypeNullable::deserializeWholeText(IColumn & column, ReadBuffer & istr, const FormatSettings & settings,
+                                                  const DataTypePtr & nested_data_type)
+{
+    return safeDeserialize<ReturnType>(column, *nested_data_type,
         [&istr]
         {
             return checkStringByFirstCharacterAndAssertTheRestCaseInsensitive("NULL", istr)
                 || checkStringByFirstCharacterAndAssertTheRest("ᴺᵁᴸᴸ", istr);
         },
-        [this, &istr, &settings] (IColumn & nested) { nested_data_type->deserializeAsWholeText(nested, istr, settings); });
+        [&nested_data_type, &istr, &settings] (IColumn & nested) { nested_data_type->deserializeAsWholeText(nested, istr, settings); });
 }
 
 
@@ -551,6 +558,7 @@ DataTypePtr removeNullable(const DataTypePtr & type)
 }
 
 
+template bool DataTypeNullable::deserializeWholeText<bool>(IColumn & column, ReadBuffer & istr, const FormatSettings & settings, const DataTypePtr & nested);
 template bool DataTypeNullable::deserializeTextEscaped<bool>(IColumn & column, ReadBuffer & istr, const FormatSettings & settings, const DataTypePtr & nested);
 template bool DataTypeNullable::deserializeTextQuoted<bool>(IColumn & column, ReadBuffer & istr, const FormatSettings &, const DataTypePtr & nested);
 template bool DataTypeNullable::deserializeTextCSV<bool>(IColumn & column, ReadBuffer & istr, const FormatSettings & settings, const DataTypePtr & nested);

src/DataTypes/DataTypeNullable.h

@@ -103,6 +103,8 @@ public:
     /// If ReturnType is bool, check for NULL and deserialize value into non-nullable column (and return true) or insert default value of nested type (and return false)
     /// If ReturnType is void, deserialize Nullable(T)
     template <typename ReturnType = bool>
+    static ReturnType deserializeWholeText(IColumn & column, ReadBuffer & istr, const FormatSettings & settings, const DataTypePtr & nested);
+    template <typename ReturnType = bool>
     static ReturnType deserializeTextEscaped(IColumn & column, ReadBuffer & istr, const FormatSettings & settings, const DataTypePtr & nested);
     template <typename ReturnType = bool>
     static ReturnType deserializeTextQuoted(IColumn & column, ReadBuffer & istr, const FormatSettings &, const DataTypePtr & nested);

src/Processors/Formats/Impl/JSONCompactEachRowRowInputFormat.cpp

@@ -205,14 +205,15 @@ void JSONCompactEachRowRowInputFormat::readField(size_t index, MutableColumns &
 
         if (yield_strings)
         {
-            // notice: null_as_default on "null" strings is not supported
-
             String str;
             readJSONString(str, in);
 
             ReadBufferFromString buf(str);
 
-            type->deserializeAsWholeText(*columns[index], buf, format_settings);
+            if (format_settings.null_as_default && !type->isNullable())
+                read_columns[index] = DataTypeNullable::deserializeWholeText(*columns[index], buf, format_settings, type);
+            else
+                type->deserializeAsWholeText(*columns[index], buf, format_settings);
         }
         else
         {

src/Processors/Formats/Impl/JSONEachRowRowInputFormat.cpp

@@ -146,14 +146,15 @@ void JSONEachRowRowInputFormat::readField(size_t index, MutableColumns & columns
 
         if (yield_strings)
         {
-            // notice: null_as_default on "null" strings is not supported
-
             String str;
             readJSONString(str, in);
 
             ReadBufferFromString buf(str);
 
-            type->deserializeAsWholeText(*columns[index], buf, format_settings);
+            if (format_settings.null_as_default && !type->isNullable())
+                read_columns[index] = DataTypeNullable::deserializeWholeText(*columns[index], buf, format_settings, type);
+            else
+                type->deserializeAsWholeText(*columns[index], buf, format_settings);
         }
         else
         {

tests/queries/0_stateless/01016_input_null_as_default.reference

@@ -18,6 +18,11 @@ JSONEachRow
 1	world	3	2019-07-23	[1,2,3]	('tuple',3.14)
 2	Hello	123	2019-06-19	[]	('test',2.71828)
 3	Hello	42	2019-06-19	[1,2,3]	('default',0.75)
+JSONStringsEachRow
+0	1	42	2019-07-22	[10,20,30]	('default',0)
+1	world	3	2019-07-23	[1,2,3]	('tuple',3.14)
+2	Hello	123	2019-06-19	[]	('test',2.71828)
+3	Hello	42	2019-06-19	[1,2,3]	('default',0.75)
 Template (Quoted)
 0	1	42	2019-07-22	[10,20,30]	('default',0)
 1	world	3	2019-07-23	[1,2,3]	('tuple',3.14)

tests/queries/0_stateless/01016_input_null_as_default.sh

@@ -38,6 +38,14 @@ echo '{"i": null, "s": "1", "n": null, "d": "2019-07-22", "a": [10, 20, 30], "t"
 $CLICKHOUSE_CLIENT --query="SELECT * FROM null_as_default ORDER BY i";
 $CLICKHOUSE_CLIENT --query="TRUNCATE TABLE null_as_default";
 
+echo 'JSONStringsEachRow'
+echo '{"i": "null", "s": "1", "n": "ᴺᵁᴸᴸ", "d": "2019-07-22", "a": "[10, 20, 30]", "t": "NULL"}
+{"i": "1", "s": "world", "n": "3", "d": "2019-07-23", "a": "null", "t": "('\''tuple'\'', 3.14)"}
+{"i": "2", "s": "null", "n": "123", "d": "null", "a": "[]", "t": "('\''test'\'', 2.71828)"}
+{"i": "3", "s": "null", "n": "null", "d": "null", "a": "null", "t": "null"}' | $CLICKHOUSE_CLIENT --input_format_null_as_default=1 --query="INSERT INTO null_as_default FORMAT JSONStringsEachRow";
+$CLICKHOUSE_CLIENT --query="SELECT * FROM null_as_default ORDER BY i";
+$CLICKHOUSE_CLIENT --query="TRUNCATE TABLE null_as_default";
+
 echo 'Template (Quoted)'
 echo 'NULL, '\''1'\'', null, '\''2019-07-22'\'', [10, 20, 30], NuLl
 1, '\''world'\'', 3, '\''2019-07-23'\'', NULL, ('\''tuple'\'', 3.14)