fix(Data): Poco::Data::ODBC-dbEncoding property not used for insert/update #3396

Data/ODBC/include/Poco/Data/ODBC/Binder.h

@@ -71,7 +71,9 @@ public:
 	Binder(const StatementHandle& rStmt,
 		std::size_t maxFieldSize,
 		ParameterBinding dataBinding = PB_IMMEDIATE,
-		const TypeInfo* pDataTypes = 0);
+		const TypeInfo* pDataTypes = 0,
+		Poco::TextEncoding::Ptr pFromEncoding = nullptr,
+		Poco::TextEncoding::Ptr pDBEncoding = nullptr);
 		/// Creates the Binder.
 
 	~Binder();
@@ -538,7 +540,7 @@ private:
 	}
 
 	template <typename C>
-	void bindImplContainerString(std::size_t pos, const C& val, Direction dir)
+	void bindImplContainerString(std::size_t pos, const C& valC, Direction dir)
 		/// Utility function to bind containers of strings.
 	{
 		if (isOutBound(dir) || !isInBound(dir))
@@ -547,7 +549,19 @@ private:
 		if (PB_IMMEDIATE != _paramBinding)
 			throw InvalidAccessException("Containers can only be bound immediately.");
 
-		std::size_t length = val.size();
+		const C* pVal = 0;
+		if (!transcodeRequired()) pVal = &valC;
+		else
+		{
+			pVal = new C(valC.size());
+			typename C::const_iterator valIt = valC.begin();
+			typename C::const_iterator valEnd = valC.end();
+			typename C::iterator tcIt = const_cast<C*>(pVal)->begin();
+			for (; valIt != valEnd; ++valIt, ++tcIt)
+				transcode(*valIt, *tcIt);
+		}
+
+		std::size_t length = pVal->size();
 
 		if (0 == length)
 			throw InvalidArgumentException("Empty container not allowed.");
@@ -560,7 +574,7 @@ private:
 
 		if (size == _maxFieldSize)
 		{
-			getMinValueSize(val, size);
+			getMinValueSize(*pVal, size);
 			// accomodate for terminating zero
 			if (size != _maxFieldSize) ++size;
 		}
@@ -574,20 +588,25 @@ private:
 		if (_charPtrs.size() <= pos)
 			_charPtrs.resize(pos + 1, 0);
 
-		_charPtrs[pos] = (char*) std::calloc(val.size() * size, sizeof(char));
+		_charPtrs[pos] = (char*) std::calloc(pVal->size() * size, sizeof(char));
 
+		std::string typeID = typeid(*pVal).name();
 		std::size_t strSize;
 		std::size_t offset = 0;
-		typename C::const_iterator it = val.begin();
+		typename C::const_iterator it = pVal->begin();
-		typename C::const_iterator end = val.end();
+		typename C::const_iterator end = pVal->end();
 		for (; it != end; ++it)
 		{
 			strSize = it->size();
 			if (strSize > size)
-				throw LengthExceededException("SQLBindParameter(std::vector<std::string>)");
+			{
+				if (transcodeRequired()) delete pVal;
+				throw LengthExceededException(Poco::format("SQLBindParameter(%s)", typeID));
+			}
 			std::memcpy(_charPtrs[pos] + offset, it->c_str(), strSize);
 			offset += size;
 		}
+		if (transcodeRequired()) delete pVal;
 
 		if (Utility::isError(SQLBindParameter(_rStmt,
 			(SQLUSMALLINT) pos + 1,
@@ -600,7 +619,7 @@ private:
 			(SQLINTEGER) size,
 			&(*_vecLengthIndicator[pos])[0])))
 		{
-			throw StatementException(_rStmt, "SQLBindParameter(std::vector<std::string>)");
+			throw StatementException(_rStmt, Poco::format("SQLBindParameter(%s)", typeID));
 		}
 	}
 

Data/ODBC/include/Poco/Data/ODBC/Extractor.h

@@ -55,7 +55,8 @@ public:
 
 	Extractor(const StatementHandle& rStmt,
 		Preparator::Ptr pPreparator,
-		Poco::TextEncoding::Ptr pDBEncoding = nullptr);
+		Poco::TextEncoding::Ptr pDBEncoding = nullptr,
+		Poco::TextEncoding::Ptr pToEncoding = nullptr);
 		/// Creates the Extractor.
 
 	~Extractor();

Data/ODBC/src/Binder.cpp

@@ -30,7 +30,10 @@ namespace ODBC {
 Binder::Binder(const StatementHandle& rStmt,
 	std::size_t maxFieldSize,
 	Binder::ParameterBinding dataBinding,
-	const TypeInfo* pDataTypes):
+	const TypeInfo* pDataTypes,
+	Poco::TextEncoding::Ptr pFromEncoding,
+	Poco::TextEncoding::Ptr pDBEncoding):
+	Poco::Data::AbstractBinder(pFromEncoding, pDBEncoding),
 	_rStmt(rStmt),
 	_paramBinding(dataBinding),
 	_pTypeInfo(pDataTypes),
@@ -99,13 +102,30 @@ void Binder::freeMemory()
 	DateTimeVecVec::iterator itDateTimeVec = _dateTimeVecVec.begin();
 	DateTimeVecVec::iterator itDateTimeVecEnd = _dateTimeVecVec.end();
 	for (; itDateTimeVec != itDateTimeVecEnd; ++itDateTimeVec) delete *itDateTimeVec;
+
+	if (transcodeRequired() && _inParams.size())
+	{
+		ParamMap::iterator itInParams = _inParams.begin();
+		ParamMap::iterator itInParamsEnd = _inParams.end();
+		for (; itInParams != itInParamsEnd; ++itInParams) free(itInParams->first);
+	}
 }
 
 
 void Binder::bind(std::size_t pos, const std::string& val, Direction dir)
 {
+	char* pTCVal = 0;
+	SQLINTEGER size = 0;
+	if (transcodeRequired())
+	{
+		std::string tcVal;
+		transcode(val, tcVal);
+		size = (SQLINTEGER)tcVal.size();
+		pTCVal = reinterpret_cast<char*>(std::calloc((size_t)size+1, 1));
+		std::memcpy(pTCVal, tcVal.data(), size);
+	}
+	else size = (SQLINTEGER)val.size();
 	SQLPOINTER pVal = 0;
-	SQLINTEGER size = (SQLINTEGER) val.size();
 	SQLINTEGER colSize = 0;
 	SQLSMALLINT decDigits = 0;
 	getColSizeAndPrecision(pos, SQL_C_CHAR, colSize, decDigits, val.size());
@@ -120,9 +140,17 @@ void Binder::bind(std::size_t pos, const std::string& val, Direction dir)
 	}
 	else if (isInBound(dir))
 	{
-		pVal = (SQLPOINTER) val.c_str();
+		if (!pTCVal)
+		{
+			pVal = (SQLPOINTER)val.c_str();
 			_inParams.insert(ParamMap::value_type(pVal, size));
 		}
+		else
+		{
+			pVal = (SQLPOINTER)pTCVal;
+			_inParams.insert(ParamMap::value_type(pVal, size));
+		}
+	}
 	else
 		throw InvalidArgumentException("Parameter must be [in] OR [out] bound.");
 
@@ -421,13 +449,29 @@ void Binder::synchronize()
 			Utility::dateTimeSync(*it->second, *it->first);
 	}
 
+	if (!transcodeRequired())
+	{
 		if (_strings.size())
 		{
 			StringMap::iterator it = _strings.begin();
 			StringMap::iterator end = _strings.end();
-		for(; it != end; ++it)
+			for (; it != end; ++it)
 				it->second->assign(it->first, std::strlen(it->first));
 		}
+	}
+	else
+	{
+		if (_strings.size())
+		{
+			StringMap::iterator it = _strings.begin();
+			StringMap::iterator end = _strings.end();
+			for (; it != end; ++it)
+			{
+				std::string str(it->first, std::strlen(it->first));
+				reverseTranscode(str, *it->second);
+			}
+		}
+	}
 
 	if (_uuids.size())
 	{

Data/ODBC/src/ConnectionHandle.cpp

@@ -15,6 +15,8 @@
 #include "Poco/Data/ODBC/ConnectionHandle.h"
 #include "Poco/Data/ODBC/Utility.h"
 #include "Poco/Data/ODBC/ODBCException.h"
+#include "Poco/Error.h"
+#include "Poco/Debugger.h"
 
 
 namespace Poco {
@@ -42,10 +44,11 @@ ConnectionHandle::~ConnectionHandle()
 	{
 		SQLDisconnect(_hdbc);
 		SQLRETURN rc = SQLFreeHandle(SQL_HANDLE_DBC, _hdbc);
-
 		if (_ownsEnvironment) delete _pEnvironment;
-
+#if defined(_DEBUG)
-		poco_assert (!Utility::isError(rc));
+		if (Utility::isError(rc))
+			Debugger::enter(Poco::Error::getMessage(Poco::Error::last()), __FILE__, __LINE__);
+#endif
 	}
 	catch (...)
 	{

Data/ODBC/src/EnvironmentHandle.cpp

@@ -15,6 +15,8 @@
 #include "Poco/Data/ODBC/EnvironmentHandle.h"
 #include "Poco/Data/ODBC/Utility.h"
 #include "Poco/Data/ODBC/ODBCException.h"
+#include "Poco/Error.h"
+#include "Poco/Debugger.h"
 
 
 namespace Poco {
@@ -42,7 +44,10 @@ EnvironmentHandle::~EnvironmentHandle()
 	try
 	{
 		SQLRETURN rc = SQLFreeHandle(SQL_HANDLE_ENV, _henv);
-		poco_assert (!Utility::isError(rc));
+#if defined(_DEBUG)
+		if (Utility::isError(rc))
+			Debugger::enter(Poco::Error::getMessage(Poco::Error::last()), __FILE__, __LINE__);
+#endif
 	}
 	catch (...)
 	{

Data/ODBC/src/Extractor.cpp

@@ -35,7 +35,8 @@ const std::string Extractor::FLD_SIZE_EXCEEDED_FMT = "Specified data size (%z by
 
 Extractor::Extractor(const StatementHandle& rStmt,
 	Preparator::Ptr pPreparator,
-	TextEncoding::Ptr pDBEncoding): AbstractExtractor(pDBEncoding),
+	TextEncoding::Ptr pDBEncoding,
+	Poco::TextEncoding::Ptr pToEncoding): AbstractExtractor(pDBEncoding, pToEncoding),
 	_rStmt(rStmt),
 	_pPreparator(pPreparator),
 	_dataExtraction(pPreparator->getDataExtraction())
@@ -719,6 +720,7 @@ bool Extractor::extract(std::size_t pos, std::string& val)
 		else
 			ret = extractBoundImpl(pos, result);
 		transcode(result, val);
+		
 	}
 
 	return ret;

Data/ODBC/src/ODBCStatementImpl.cpp

@@ -98,7 +98,8 @@ void ODBCStatementImpl::compileImpl()
 
 	std::size_t maxFieldSize = AnyCast<std::size_t>(session().getProperty("maxFieldSize"));
 
-	_pBinder = new Binder(_stmt, maxFieldSize, bind, pDT);
+	_pBinder = new Binder(_stmt, maxFieldSize, bind, pDT, TextEncoding::find("UTF-8"),
+		TextEncoding::find(Poco::RefAnyCast<std::string>(session().getProperty("dbEncoding"))));
 
 	makeInternalExtractors();
 	doPrepare();
@@ -146,7 +147,8 @@ void ODBCStatementImpl::addPreparator()
 		_preparations.push_back(new Preparator(*_preparations[0]));
 
 	_extractors.push_back(new Extractor(_stmt, _preparations.back(),
-		TextEncoding::find(Poco::RefAnyCast<std::string>(session().getProperty("dbEncoding")))));
+		TextEncoding::find(Poco::RefAnyCast<std::string>(session().getProperty("dbEncoding"))),
+		TextEncoding::find("UTF-8")));
 }
 
 

Data/ODBC/testsuite/src/ODBCSQLServerTest.cpp

@@ -87,6 +87,7 @@ using Poco::DateTime;
 
 
 ODBCTest::SessionPtr ODBCSQLServerTest::_pSession;
+ODBCTest::SessionPtr ODBCSQLServerTest::_pEncSession;
 ODBCTest::ExecPtr    ODBCSQLServerTest::_pExecutor;
 std::string          ODBCSQLServerTest::_driver = MS_SQL_SERVER_ODBC_DRIVER;
 std::string          ODBCSQLServerTest::_dsn = MS_SQL_SERVER_DSN;
@@ -733,13 +734,28 @@ void ODBCSQLServerTest::recreateUnicodeTable()
 }
 
 
+void ODBCSQLServerTest::recreateEncodingTables()
+{
+#if defined (POCO_ODBC_UNICODE)
+	dropObject("TABLE", "Latin1Table");
+	try { session() << "CREATE TABLE Latin1Table (str NVARCHAR(30))", now; }
+	catch (ConnectionException& ce) { std::cout << ce.toString() << std::endl; fail("recreateEncodingTables()"); }
+	catch (StatementException& se) { std::cout << se.toString() << std::endl; fail("recreateEncodingTables()"); }
+#endif
+}
+
+
 CppUnit::Test* ODBCSQLServerTest::suite()
 {
 	if ((_pSession = init(_driver, _dsn, _uid, _pwd, _connectString, _db)))
 	{
 		std::cout << "*** Connected to [" << _driver << "] test database." << std::endl;
+		std::string enc = "Latin1";
+		if ((_pEncSession = init(_driver, _dsn, _uid, _pwd, _connectString, _db, enc)))
+			std::cout << "*** Connected to [" << _driver << "] test database, encoding: [" << enc << "]." << std::endl;
+		// ...
 
-		_pExecutor = new SQLExecutor(_driver + " SQL Executor", _pSession);
+		_pExecutor = new SQLExecutor(_driver + " SQL Executor", _pSession, _pEncSession);
 
 		CppUnit::TestSuite* pSuite = new CppUnit::TestSuite("ODBCSQLServerTest");
 
@@ -822,6 +838,7 @@ CppUnit::Test* ODBCSQLServerTest::suite()
 		CppUnit_addTest(pSuite, ODBCSQLServerTest, testTransactor);
 		CppUnit_addTest(pSuite, ODBCSQLServerTest, testNullable);
 		CppUnit_addTest(pSuite, ODBCSQLServerTest, testUnicode);
+		CppUnit_addTest(pSuite, ODBCSQLServerTest, testEncoding);
 		CppUnit_addTest(pSuite, ODBCSQLServerTest, testReconnect);
 
 		return pSuite;

Data/ODBC/testsuite/src/ODBCSQLServerTest.h

@@ -74,8 +74,10 @@ private:
 	void recreateMiscTable();
 	void recreateLogTable();
 	void recreateUnicodeTable();
+	void recreateEncodingTables();
 
 	static SessionPtr  _pSession;
+	static SessionPtr  _pEncSession;
 	static ExecPtr     _pExecutor;
 	static std::string _driver;
 	static std::string _dsn;

Data/ODBC/testsuite/src/ODBCTest.cpp

@@ -1252,6 +1252,25 @@ void ODBCTest::testUnicode()
 }
 
 
+void ODBCTest::testEncoding()
+{
+#if defined (POCO_ODBC_UNICODE)
+	if (!_pSession) fail("Test not available.");
+
+	for (int i = 0; i < 8;)
+	{
+		recreateEncodingTables();
+		_pSession->setFeature("autoBind", bindValue(i));
+		_pSession->setFeature("autoExtract", bindValue(i + 1));
+		_pExecutor->encoding(_rConnectString);
+		i += 2;
+	}
+#else
+	std::cout << "Not an UNICODE build, skipping." << std::endl;
+#endif
+}
+
+
 void ODBCTest::testReconnect()
 {
 	if (!_pSession) fail ("Test not available.");
@@ -1341,7 +1360,8 @@ ODBCTest::SessionPtr ODBCTest::init(const std::string& driver,
 	std::string& uid,
 	std::string& pwd,
 	std::string& dbConnString,
-	const std::string& db)
+	const std::string& db,
+	const std::string& dbEncoding)
 {
 	Utility::drivers(_drivers);
 	if (!canConnect(driver, dsn, uid, pwd, dbConnString, db)) return 0;
@@ -1349,7 +1369,10 @@ ODBCTest::SessionPtr ODBCTest::init(const std::string& driver,
 	try
 	{
 		std::cout << "Conecting to [" << dbConnString << ']' << std::endl;
-		return new Session(Poco::Data::ODBC::Connector::KEY, dbConnString, 5);
+		SessionPtr ptr = new Session(Poco::Data::ODBC::Connector::KEY, dbConnString, 5);
+		if (!dbEncoding.empty())
+			ptr->setProperty("dbEncoding", dbEncoding);
+		return ptr;
 	}catch (ConnectionFailedException& ex)
 	{
 		std::cout << ex.displayText() << std::endl;

Data/ODBC/testsuite/src/ODBCTest.h

@@ -151,6 +151,7 @@ public:
 	virtual void testNullable();
 
 	virtual void testUnicode();
+	virtual void testEncoding();
 
 	virtual void testReconnect();
 
@@ -177,13 +178,15 @@ protected:
 	virtual void recreateMiscTable();
 	virtual void recreateLogTable();
 	virtual void recreateUnicodeTable();
+	virtual void recreateEncodingTables();
 
 	static SessionPtr init(const std::string& driver,
 		std::string& dsn,
 		std::string& uid,
 		std::string& pwd,
 		std::string& dbConnString,
-		const std::string& db = "");
+		const std::string& db = "",
+		const std::string& dbEncoding = "");
 
 	static bool canConnect(const std::string& driver,
 		std::string& dsn,
@@ -374,6 +377,12 @@ inline void ODBCTest::recreateUnicodeTable()
 }
 
 
+inline void ODBCTest::recreateEncodingTables()
+{
+	throw Poco::NotImplementedException("ODBCTest::recreateUnicodeTables()");
+}
+
+
 inline bool ODBCTest::bindValue(int i) 
 { 
 	poco_assert (i < 8);

Data/ODBC/testsuite/src/SQLExecutor.cpp

@@ -296,9 +296,10 @@ const std::string SQLExecutor::MULTI_SELECT =
 	"SELECT * FROM Test WHERE First = '5';";
 
 
-SQLExecutor::SQLExecutor(const std::string& name, Poco::Data::Session* pSession): 
+SQLExecutor::SQLExecutor(const std::string& name, Poco::Data::Session* pSession, Poco::Data::Session* pEncSession):
 	CppUnit::TestCase(name),
-	_pSession(pSession)
+	_pSession(pSession),
+	_pEncSession(pEncSession)
 {
 }
 
@@ -3530,6 +3531,7 @@ void SQLExecutor::sqlLogger(const std::string& connect)
 		rs.moveNext();
 		assertTrue ("TestSQLChannel" == rs["Source"]);
 		assertTrue ("b Warning message" == rs["Text"]);
+		root.setChannel(nullptr);
 	} 
 	catch(ConnectionException& ce){ std::cout << ce.toString() << std::endl; fail ("sqlLogger()"); }
 	catch(StatementException& se){ std::cout << se.toString() << std::endl; fail ("sqlLogger()"); }
@@ -4034,3 +4036,54 @@ void SQLExecutor::unicode(const std::string& dbConnString)
 	Poco::UnicodeConverter::convert(wtext, text);
 	assertTrue (text == std::string((const char*)supp));
 }
+
+
+void SQLExecutor::encoding(const std::string& dbConnString)
+{
+	try
+	{
+		const unsigned char latinChars[] = { 'g', 252, 'n', 't', 'e', 'r', 0 };
+		const unsigned char utf8Chars[] = { 'g', 195, 188, 'n', 't', 'e', 'r', 0 };
+		std::string latinText((const char*)latinChars);
+		std::string utf8TextIn((const char*)utf8Chars);
+
+		session(true) << "INSERT INTO Latin1Table VALUES (?)", use(utf8TextIn), now;
+
+		std::string latinTextOut;
+		session() << "SELECT str FROM Latin1Table", into(latinTextOut), now;
+		assertTrue(latinText == latinTextOut);
+
+		std::string utf8TextOut;
+		session(true) << "SELECT str FROM Latin1Table", into(utf8TextOut), now;
+		assertTrue(utf8TextIn == utf8TextOut);
+
+		const unsigned char latinChars2[] = { 'G', 220, 'N', 'T', 'E', 'R', 0 };
+		const unsigned char utf8Chars2[] = { 'G', 195, 156, 'N', 'T', 'E', 'R', 0 };
+		std::string latinText2 = (const char*)latinChars2;
+		std::string utf8TextIn2 = (const char*)utf8Chars2;
+
+		session(true) << "INSERT INTO Latin1Table VALUES (?)", use(utf8TextIn2), now;
+
+		std::vector<std::string> textOutVec;
+		session() << "SELECT str FROM Latin1Table", into(textOutVec), now;
+		assertTrue(textOutVec.size() == 2);
+		assertTrue(textOutVec[0] == latinText);
+		assertTrue(textOutVec[1] == latinText2);
+
+		textOutVec.clear();
+		session(true) << "SELECT str FROM Latin1Table", into(textOutVec), now;
+		assertTrue(textOutVec.size() == 2);
+		assertTrue(textOutVec[0] == utf8TextIn);
+		assertTrue(textOutVec[1] == utf8TextIn2);
+	}
+	catch (Poco::Exception& ex)
+	{
+		std::cout << ex.displayText() << std::endl;
+		throw;
+	}
+	catch (std::exception& ex)
+	{
+		std::cout << ex.what() << std::endl;
+		throw;
+	}
+}

Data/ODBC/testsuite/src/SQLExecutor.h

@@ -87,7 +87,7 @@ public:
 		DE_BOUND
 	};
 
-	SQLExecutor(const std::string& name, Poco::Data::Session* _pSession);
+	SQLExecutor(const std::string& name, Poco::Data::Session* pSession, Poco::Data::Session* pEncSession = 0);
 	~SQLExecutor();
 
 	void execute(const std::string& sql);
@@ -505,6 +505,7 @@ public:
 	void nullable();
 
 	void unicode(const std::string& dbConnString);
+	void encoding(const std::string& dbConnString);
 
 	void reconnect();
 
@@ -514,15 +515,24 @@ private:
 
 	void setTransactionIsolation(Poco::Data::Session& session, Poco::UInt32 ti);
 
-	Poco::Data::Session& session();
+	Poco::Data::Session& session(bool enc = false);
 	Poco::Data::Session* _pSession;
+	Poco::Data::Session* _pEncSession;
 };
 
 
-inline Poco::Data::Session& SQLExecutor::session()
+inline Poco::Data::Session& SQLExecutor::session(bool enc)
 {
-	poco_check_ptr (_pSession);
+	if (!enc)
+	{
+		poco_check_ptr(_pSession);
 		return *_pSession;
+	}
+	else
+	{
+		poco_check_ptr(_pEncSession);
+		return *_pEncSession;
+	}
 }
 
 

Data/include/Poco/Data/AbstractBinder.h

@@ -28,6 +28,7 @@
 #include "Poco/Any.h"
 #include "Poco/Dynamic/Var.h"
 #include "Poco/UTFString.h"
+#include "Poco/TextEncoding.h"
 #include <vector>
 #include <deque>
 #include <list>
@@ -39,7 +40,7 @@ namespace Data {
 
 
 using NullData = NullType;
-
+class Transcoder;
 
 namespace Keywords {
 
@@ -64,7 +65,8 @@ public:
 		PD_IN_OUT
 	};
 
-	AbstractBinder();
+	AbstractBinder(Poco::TextEncoding::Ptr pFromEncoding = nullptr,
+		Poco::TextEncoding::Ptr pDBEncoding = nullptr);
 		/// Creates the AbstractBinder.
 
 	virtual ~AbstractBinder();
@@ -356,6 +358,14 @@ public:
 
 	static bool isInBound(Direction dir);
 		/// Returns true if direction is in bound;
+
+protected:
+	bool transcodeRequired() const;
+	void transcode(const std::string& from, std::string& to);
+	void reverseTranscode(const std::string& from, std::string& to);
+
+private:
+	std::unique_ptr<Transcoder> _pTranscoder;
 };
 
 
@@ -380,6 +390,12 @@ inline bool AbstractBinder::isInBound(Direction dir)
 }
 
 
+inline bool AbstractBinder::transcodeRequired() const
+{
+	return _pTranscoder.operator bool();
+}
+
+
 } } // namespace Poco::Data
 
 

Data/include/Poco/Data/AbstractExtractor.h

@@ -23,7 +23,6 @@
 #include "Poco/Data/LOB.h"
 #include "Poco/UUID.h"
 #include "Poco/UTFString.h"
-#include "Poco/TextConverter.h"
 #include "Poco/TextEncoding.h"
 #include <memory>
 #include <vector>
@@ -35,7 +34,6 @@
 
 namespace Poco {
 
-
 class DateTime;
 class Any;
 
@@ -48,6 +46,7 @@ namespace Data {
 
 class Date;
 class Time;
+class Transcoder;
 
 
 class Data_API AbstractExtractor
@@ -353,18 +352,18 @@ public:
 
 protected:
 	bool transcodeRequired() const;
-	void transcode(const std::string& val1, std::string& val2);
+	void transcode(const std::string& from, std::string& to);
+	void reverseTranscode(const std::string& from, std::string& to);
 
 private:
-	Poco::TextEncoding::Ptr _pDBEncoding;
+	std::unique_ptr<Transcoder> _pTranscoder;
-	Poco::TextEncoding::Ptr _pToEncoding;
-	std::unique_ptr<Poco::TextConverter> _pConverter;
 };
 
 
 ///
 /// inlines
 ///
+
 inline void AbstractExtractor::reset()
 {
 	//default no-op
@@ -373,17 +372,7 @@ inline void AbstractExtractor::reset()
 
 inline bool AbstractExtractor::transcodeRequired() const
 {
-	return _pConverter.operator bool();
+	return _pTranscoder.operator bool();
-}
-
-
-inline void AbstractExtractor::transcode(const std::string& val1, std::string& val2)
-{
-	if (_pConverter)
-	{
-		val2.clear();
-		_pConverter->convert(val1, val2);
-	}
 }
 
 

Data/include/Poco/Data/Binding.h

@@ -47,7 +47,7 @@ class Binding: public AbstractBinding
 	/// is passed to binding, the storage it refers to must be valid at the statement execution time.
 	/// To pass a copy of a variable, constant or string literal, use utility function bind().
 	/// Variables can be passed as either copies or references (i.e. using either use() or bind()).
-	/// Constants, however, can only be passed as copies. this is best achieved using bind() utility 
+	/// Constants, however, can only be passed as copies. This is best achieved using bind() utility
 	/// function. An attempt to pass a constant by reference shall result in compile-time error.
 {
 public:

Data/include/Poco/Data/Transcoder.h

@@ -0,0 +1,97 @@
+//
+// Transcoder.h
+//
+// Library: Data
+// Package: DataCore
+// Module:  Transcoder
+//
+// Definition of the Transcoder class.
+//
+// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#ifndef Data_Transcoder_INCLUDED
+#define Data_Transcoder_INCLUDED
+
+
+#include "Poco/Data/Data.h"
+#include "Poco/TextConverter.h"
+#include "Poco/TextEncoding.h"
+#include <memory>
+#include <string>
+
+
+namespace Poco {
+namespace Data {
+
+
+class Data_API Transcoder
+	/// Utility class used to convert string data encoding.
+	///
+	/// The purpose of this class is to help with deciding
+	/// whether conversion is actually required, and to keep
+	/// the encodings lifetimes aligned with the converter lifetime.
+{
+public:
+	using Ptr = std::unique_ptr<Transcoder>;
+	using ConverterPtr = std::unique_ptr<Poco::TextConverter>;
+
+	virtual ~Transcoder();
+		/// Destroys the Transcoder.
+
+	static Ptr create(Poco::TextEncoding::Ptr pFromEncoding = nullptr,
+		Poco::TextEncoding::Ptr pToEncoding = nullptr);
+		/// Returns a unique pointer to Transcode instance;
+		/// if there is no need for transcoding, null pointer
+		/// is returned.
+
+	std::string fromEncoding() const;
+		/// Returns "from" encoding canonical name.
+
+	std::string toEncoding() const;
+		/// Returns "from" encoding canonical name.
+
+	void transcode(const std::string& from, std::string& to);
+		/// Performs the conversion. Any prior content of the
+		/// destination string is cleared.
+
+	void reverseTranscode(const std::string& from, std::string& to);
+		/// Performs the reverse conversion. Any prior content of the
+		/// destination string is cleared.
+
+private:
+	Transcoder(Poco::TextEncoding::Ptr pFromEncoding,
+		Poco::TextEncoding::Ptr pToEncoding);
+		/// Creates the Transcoder.
+
+	Poco::TextEncoding::Ptr _pFromEncoding;
+	Poco::TextEncoding::Ptr _pToEncoding;
+	ConverterPtr _pConverter;
+	ConverterPtr _pReverseConverter;
+};
+
+
+//
+// inlines
+//
+
+inline std::string Transcoder::fromEncoding() const
+{
+	return _pFromEncoding->canonicalName();
+}
+
+
+inline std::string Transcoder::toEncoding() const
+{
+	return _pToEncoding->canonicalName();
+}
+
+
+} } // namespace Poco::Data
+
+
+#endif // Data_Transcoder_INCLUDED

Data/src/AbstractBinder.cpp

@@ -16,6 +16,7 @@
 #include "Poco/Data/Date.h"
 #include "Poco/Data/Time.h"
 #include "Poco/Data/LOB.h"
+#include "Poco/Data/Transcoder.h"
 #include "Poco/Data/DataException.h"
 #include "Poco/DateTime.h"
 #include "Poco/Any.h"
@@ -26,7 +27,9 @@ namespace Poco {
 namespace Data {
 
 
-AbstractBinder::AbstractBinder()
+AbstractBinder::AbstractBinder(Poco::TextEncoding::Ptr pFromEncoding,
+	Poco::TextEncoding::Ptr pDBEncoding) :
+		_pTranscoder(Transcoder::create(pFromEncoding, pDBEncoding))
 {
 }
 
@@ -36,6 +39,20 @@ AbstractBinder::~AbstractBinder()
 }
 
 
+void AbstractBinder::transcode(const std::string& from, std::string& to)
+{
+	if (_pTranscoder)
+		_pTranscoder->transcode(from, to);
+}
+
+
+void AbstractBinder::reverseTranscode(const std::string& from, std::string& to)
+{
+	if (_pTranscoder)
+		_pTranscoder->reverseTranscode(from, to);
+}
+
+
 void AbstractBinder::bind(std::size_t pos, const std::vector<Poco::Int8>& val, Direction dir)
 {
 	throw NotImplementedException("std::vector binder must be implemented.");

Data/src/AbstractExtractor.cpp

@@ -13,6 +13,7 @@
 
 
 #include "Poco/Data/AbstractExtractor.h"
+#include "Poco/Data/Transcoder.h"
 #include "Poco/Exception.h"
 
 
@@ -22,16 +23,8 @@ namespace Data {
 
 AbstractExtractor::AbstractExtractor(Poco::TextEncoding::Ptr pDBEncoding,
 	Poco::TextEncoding::Ptr pToEncoding):
-	_pDBEncoding(pDBEncoding),
+	_pTranscoder(Transcoder::create(pDBEncoding, pToEncoding))
-	_pToEncoding(pToEncoding ?
-		pToEncoding : _pDBEncoding ?
-			Poco::TextEncoding::find("UTF-8") : nullptr),
-	_pConverter(_pDBEncoding ?
-		new Poco::TextConverter(*pDBEncoding, *_pToEncoding) :
-		nullptr)
 {
-	poco_assert_dbg((!_pDBEncoding && !_pToEncoding) ||
-		(_pDBEncoding && _pToEncoding));
 }
 
 
@@ -40,6 +33,20 @@ AbstractExtractor::~AbstractExtractor()
 }
 
 
+void AbstractExtractor::transcode(const std::string& from, std::string& to)
+{
+	if (_pTranscoder)
+		_pTranscoder->transcode(from, to);
+}
+
+
+void AbstractExtractor::reverseTranscode(const std::string& from, std::string& to)
+{
+	if (_pTranscoder)
+		_pTranscoder->reverseTranscode(from, to);
+}
+
+
 bool AbstractExtractor::extract(std::size_t pos, std::vector<Poco::Int8>& val)
 {
 	throw NotImplementedException("std::vector extractor must be implemented.");

Data/src/Transcoder.cpp

@@ -0,0 +1,76 @@
+//
+// Transcoder.cpp
+//
+// Library: Data
+// Package: DataCore
+// Module:  Transcoder
+//
+// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// SPDX-License-Identifier:	BSL-1.0
+//
+
+
+#include "Poco/Data/Transcoder.h"
+
+
+namespace Poco {
+namespace Data {
+
+
+Transcoder::Transcoder(Poco::TextEncoding::Ptr pFromEncoding,
+	Poco::TextEncoding::Ptr pToEncoding):
+	_pFromEncoding(pFromEncoding),
+	_pToEncoding(pToEncoding),
+	_pConverter(new Poco::TextConverter(*_pFromEncoding, *_pToEncoding)),
+	_pReverseConverter(new Poco::TextConverter(*_pToEncoding, *_pFromEncoding))
+{
+}
+
+
+Transcoder::~Transcoder()
+{
+}
+
+
+Transcoder::Ptr Transcoder::create(Poco::TextEncoding::Ptr pFromEncoding,
+	Poco::TextEncoding::Ptr pToEncoding)
+{
+	Ptr pTranscoder;
+
+	if (!pFromEncoding && !pToEncoding)
+		return pTranscoder;
+
+	if (!pFromEncoding) pFromEncoding = Poco::TextEncoding::find("UTF-8");
+	if (!pToEncoding) pToEncoding = Poco::TextEncoding::find("UTF-8");
+
+	if (pToEncoding->isA(pFromEncoding->canonicalName()))
+		return pTranscoder;
+	
+	pTranscoder.reset(new Transcoder(pFromEncoding, pToEncoding));
+	return pTranscoder;
+}
+
+
+void Transcoder::transcode(const std::string& from, std::string& to)
+{
+	if (_pConverter)
+	{
+		to.clear();
+		_pConverter->convert(from, to);
+	}
+}
+
+
+void Transcoder::reverseTranscode(const std::string& from, std::string& to)
+{
+	if (_pConverter)
+	{
+		to.clear();
+		_pReverseConverter->convert(from, to);
+	}
+}
+
+
+} } // namespace Poco::Data

Data/testsuite/src/DataTest.cpp

@@ -1377,6 +1377,9 @@ void DataTest::testTranscode()
 	assertTrue (ext.extract(0, utf8Out));
 	assertTrue(utf8Out == latin1Text);
 
+	Latin1Encoding::Ptr pe = new Latin1Encoding();
+	auto pUTF8E = Poco::TextEncoding::find("UTF-8");
+
 	Poco::Data::Test::Extractor ext2(new Latin1Encoding());
 	ext2.setString(latin1Text);
 	utf8Out.clear();

ProGen/progen.properties

@@ -7,25 +7,25 @@ progen.libsuffix.release_static_md = md.lib
 progen.libsuffix.release_static_mt = mt.lib
 progen.project.guidFromName.namespaceUUID = F4193868-E4EB-4090-9A01-344E7233004B
 
-progen.postprocess.upgrade2008to2015.tool = ${system.env.VS140COMNTOOLS}\\..\\IDE\\DevEnv.exe
+progen.postprocess.upgrade2008to2015.tool = ${system.env.VS160COMNTOOLS}\\..\\IDE\\DevEnv.exe
 progen.postprocess.upgrade2008to2015.args = %;/Upgrade
 progen.postprocess.upgrade2008to2015.deleteOriginalFile = true
 progen.postprocess.upgrade2008to2015.deleteFiles = Backup;_UpgradeReport_Files;UpgradeLog.XML;UpgradeLog.htm
 progen.postprocess.upgrade2008to2015.fix2015ProjectFile = true
 
-progen.postprocess.upgrade2008to2017.tool = ${system.env.VS150COMNTOOLS}\\..\\IDE\\DevEnv.exe
+progen.postprocess.upgrade2008to2017.tool = ${system.env.VS160COMNTOOLS}\\..\\IDE\\DevEnv.exe
 progen.postprocess.upgrade2008to2017.args = %;/Upgrade
 progen.postprocess.upgrade2008to2017.deleteOriginalFile = true
 progen.postprocess.upgrade2008to2017.deleteFiles = Backup;_UpgradeReport_Files;UpgradeLog.XML;UpgradeLog.htm
 progen.postprocess.upgrade2008to2017.fix2017ProjectFile = true
 
-progen.postprocess.upgrade2008to2019.tool = ${system.env.VS150COMNTOOLS}\\..\\IDE\\DevEnv.exe
+progen.postprocess.upgrade2008to2019.tool = ${system.env.VS160COMNTOOLS}\\..\\IDE\\DevEnv.exe
 progen.postprocess.upgrade2008to2019.args = %;/Upgrade
 progen.postprocess.upgrade2008to2019.deleteOriginalFile = true
 progen.postprocess.upgrade2008to2019.deleteFiles = Backup;_UpgradeReport_Files;UpgradeLog.XML;UpgradeLog.htm
 progen.postprocess.upgrade2008to2019.fix2019ProjectFile = true
 
-progen.postprocess.upgrade2008to2022.tool = ${system.env.VS150COMNTOOLS}\\..\\IDE\\DevEnv.exe
+progen.postprocess.upgrade2008to2022.tool = ${system.env.VS160COMNTOOLS}\\..\\IDE\\DevEnv.exe
 progen.postprocess.upgrade2008to2022.args = %;/Upgrade
 progen.postprocess.upgrade2008to2022.deleteOriginalFile = true
 progen.postprocess.upgrade2008to2022.deleteFiles = Backup;_UpgradeReport_Files;UpgradeLog.XML;UpgradeLog.htm