toJSONString

src/Functions/registerFunctions.cpp

@@ -40,6 +40,7 @@ void registerFunctionsGeo(FunctionFactory &);
 void registerFunctionsIntrospection(FunctionFactory &);
 void registerFunctionsNull(FunctionFactory &);
 void registerFunctionsJSON(FunctionFactory &);
+void registerFunctionToJSONString(FunctionFactory &);
 void registerFunctionsConsistentHashing(FunctionFactory & factory);
 void registerFunctionsUnixTimestamp64(FunctionFactory & factory);
 void registerFunctionBitHammingDistance(FunctionFactory & factory);
@@ -98,6 +99,7 @@ void registerFunctions()
     registerFunctionsGeo(factory);
     registerFunctionsNull(factory);
     registerFunctionsJSON(factory);
+    registerFunctionToJSONString(factory);
     registerFunctionsIntrospection(factory);
     registerFunctionsConsistentHashing(factory);
     registerFunctionsUnixTimestamp64(factory);

src/Functions/toJSONString.cpp

@@ -0,0 +1,53 @@
+#include <Columns/ColumnString.h>
+#include <DataTypes/DataTypeString.h>
+#include <Functions/FunctionFactory.h>
+#include <Functions/IFunction.h>
+#include <IO/WriteBufferFromVector.h>
+#include <IO/WriteHelpers.h>
+
+namespace DB
+{
+namespace
+{
+    class FunctionToJSONString : public IFunction
+    {
+    public:
+        static constexpr auto name = "toJSONString";
+        static FunctionPtr create(ContextPtr) { return std::make_shared<FunctionToJSONString>(); }
+
+        String getName() const override { return name; }
+
+        size_t getNumberOfArguments() const override { return 1; }
+
+        DataTypePtr getReturnTypeImpl(const ColumnsWithTypeAndName &) const override { return std::make_shared<DataTypeString>(); }
+
+        bool useDefaultImplementationForConstants() const override { return true; }
+
+        ColumnPtr
+        executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & /*result_type*/, size_t input_rows_count) const override
+        {
+            auto res = ColumnString::create();
+            ColumnString::Chars & data_to = res->getChars();
+            ColumnString::Offsets & offsets_to = res->getOffsets();
+            offsets_to.resize(input_rows_count);
+
+            WriteBufferFromVector<ColumnString::Chars> json(data_to);
+            for (size_t i = 0; i < input_rows_count; ++i)
+            {
+                arguments[0].type->getDefaultSerialization()->serializeTextJSON(*arguments[0].column, i, json, FormatSettings());
+                writeChar(0, json);
+                offsets_to[i] = json.count();
+            }
+
+            json.finalize();
+            return res;
+        }
+    };
+}
+
+void registerFunctionToJSONString(FunctionFactory & factory)
+{
+    factory.registerFunction<FunctionToJSONString>();
+}
+
+}

tests/queries/0_stateless/01905_to_json_string.reference

@@ -0,0 +1,3 @@
+[]	2947817982	"&"	-69802.9769	"w"	-1.9158530982937093e25	["2003-05-15","1988-03-19 07:13:49","2090-04-14 03:58:26.029","91943d2e-480d-66b5-ee4c-1b5bb8eb7256"]	"½O"	[]
+[-115]	481807067	",{MM"	-170235.0663	"o"	3.3808659558052087e155	["2055-01-12","2070-08-09 03:49:21","2068-11-30 09:36:49.672","20b0e7b5-ad0e-177b-3054-c779b2a8ebe0"]	"I\\u001C"	["e57178f9-4d10-2fa1-7c2d-53c5a65c3463"]
+{"1234":"5678"}

tests/queries/0_stateless/01905_to_json_string.sql

@@ -0,0 +1,10 @@
+drop table if exists t;
+
+create table t engine Memory as select * from generateRandom('a Array(Int8), b UInt32, c Nullable(String), d Decimal32(4), e Nullable(Enum16(\'h\' = 1, \'w\' = 5 , \'o\' = -200)), f Float64, g Tuple(Date, DateTime, DateTime64, UUID), h FixedString(2), i Array(Nullable(UUID))', 10, 5, 3) limit 2;
+
+select * apply toJSONString from t;
+
+drop table t;
+
+set allow_experimental_map_type = 1;
+select toJSONString(map('1234', '5678'));