fix(ODBC): detect backend at runtime for string size; add Session::db…

…msName() #4324

Data/MySQL/include/Poco/Data/MySQL/SessionImpl.h

@@ -194,6 +194,8 @@ class MySQL_API SessionImpl: public Poco::Data::AbstractSessionImpl<SessionImpl>
 		return getValue<T>(pResult, val);
 	}
 
+	void setName();
+
 	std::string           _connector;
 	mutable SessionHandle _handle;
 	bool                  _reset;

Data/MySQL/src/SessionImpl.cpp

@@ -62,6 +62,12 @@ SessionImpl::SessionImpl(const std::string& connectionString, std::size_t loginT
 }
 
 
+void SessionImpl::setName()
+{
+	setDBMSName("MySQL"s);
+}
+
+
 void SessionImpl::open(const std::string& connect)
 {
 	if (connect != connectionString())
@@ -175,7 +181,7 @@ void SessionImpl::open(const std::string& connect)
 
 	// autocommit is initially on when a session is opened
 	AbstractSessionImpl::setAutoCommit("", true);
-
+	setName();
 	_connected = true;
 }
 

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

@@ -616,11 +616,7 @@ class ODBC_API Binder: public Poco::Data::AbstractBinder
 			toODBCDirection(dir),
 			SQL_C_CHAR,
 			Utility::sqlDataType(SQL_C_CHAR),
-#if defined(POCO_DATA_ODBC_HAVE_SQL_SERVER_EXT) && POCO_DATA_SQL_SERVER_BIG_STRINGS
-			SQL_SS_LENGTH_UNLIMITED,
-#else
-			(SQLUINTEGER)size - 1,
-#endif
+			getStringColSize(size),
 			0,
 			_charPtrs[pos],
 			(SQLINTEGER) size,
@@ -687,11 +683,7 @@ class ODBC_API Binder: public Poco::Data::AbstractBinder
 			toODBCDirection(dir),
 			SQL_C_WCHAR,
 			Utility::sqlDataType(SQL_C_WCHAR),
-#if defined(POCO_DATA_ODBC_HAVE_SQL_SERVER_EXT) && POCO_DATA_SQL_SERVER_BIG_STRINGS
-			SQL_SS_LENGTH_UNLIMITED,
-#else
-			(SQLUINTEGER)size - 1,
-#endif
+			getStringColSize(size),
 			0,
 			_utf16CharPtrs[pos],
 			(SQLINTEGER)size,
@@ -958,6 +950,11 @@ class ODBC_API Binder: public Poco::Data::AbstractBinder
 		}
 	}
 
+	SQLUINTEGER getStringColSize(SQLUINTEGER columnSize);
+		/// Returns the string column size.
+		/// If the back end is not SQL Server, it returns
+		/// the `columnSize` passed in.
+
 	void getColSizeAndPrecision(std::size_t pos,
 		SQLSMALLINT cDataType,
 		SQLINTEGER& colSize,

Data/ODBC/include/Poco/Data/ODBC/Handle.h

@@ -81,6 +81,12 @@ class Handle
 		return _handle;
 	}
 
+	const ConnectionHandle& connection() const
+		/// Returns the connection handle.
+	{
+		return _rConnection;
+	}
+
 private:
 	Handle(const Handle&);
 	const Handle& operator=(const Handle&);

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

@@ -70,7 +70,7 @@
 		// - increasing the "maxFieldSize" property may
 		//   affect performance (more memory preallocated
 		//   for prepared statements in order to safely
-		//   accomodate data returned at execution)
+		//   accommodate data returned at execution)
 		#if !defined(POCO_DATA_SQL_SERVER_BIG_STRINGS)
 			#define POCO_DATA_SQL_SERVER_BIG_STRINGS 1
 		#endif

Data/ODBC/include/Poco/Data/ODBC/SessionImpl.h

@@ -229,6 +229,9 @@ class ODBC_API SessionImpl: public Poco::Data::AbstractSessionImpl<SessionImpl>
 		/// Sets the transaction isolation level.
 		/// Called internally from getTransactionIsolation()
 
+	void setName();
+		/// Sets the back end DBMS name.
+
 	std::string                   _connector;
 	mutable ConnectionHandle      _db;
 	Poco::Any                     _maxFieldSize;

Data/ODBC/include/Poco/Data/ODBC/Utility.h

@@ -33,6 +33,9 @@ namespace Data {
 namespace ODBC {
 
 
+class ConnectionHandle;
+
+
 class ODBC_API Utility
 	/// Various utility functions
 {
@@ -162,6 +165,10 @@ class ODBC_API Utility
 		for (; it != end; ++it, ++tIt) dateTimeSync(*tIt, *it);
 	}
 
+	static std::string dbmsName(const ConnectionHandle& db);
+		/// Returns the back end DBMS name.
+		/// On error, returns "unknown".
+
 private:
 	static const TypeInfo _dataTypes;
 		/// C <==> SQL data type mapping

Data/ODBC/src/Binder.cpp

@@ -166,11 +166,7 @@ void Binder::bind(std::size_t pos, const std::string& val, Direction dir)
 		toODBCDirection(dir),
 		SQL_C_CHAR,
 		Utility::sqlDataType(SQL_C_CHAR),
-#if defined(POCO_DATA_ODBC_HAVE_SQL_SERVER_EXT) && POCO_DATA_SQL_SERVER_BIG_STRINGS
-		SQL_SS_LENGTH_UNLIMITED,
-#else
-		(SQLUINTEGER)colSize,
-#endif
+		getStringColSize(colSize),
 		0,
 		pVal,
 		(SQLINTEGER)size,
@@ -223,11 +219,7 @@ void Binder::bind(std::size_t pos, const UTF16String& val, Direction dir)
 		toODBCDirection(dir),
 		SQL_C_WCHAR,
 		Utility::sqlDataType(SQL_C_WCHAR),
-#if defined(POCO_DATA_ODBC_HAVE_SQL_SERVER_EXT) && POCO_DATA_SQL_SERVER_BIG_STRINGS
-		SQL_SS_LENGTH_UNLIMITED,
-#else
-		(SQLUINTEGER)colSize,
-#endif
+		getStringColSize(colSize),
 		0,
 		pVal,
 		(SQLINTEGER)size,
@@ -514,6 +506,16 @@ void Binder::reset()
 }
 
 
+SQLUINTEGER Binder::getStringColSize(SQLUINTEGER columnSize)
+{
+#if defined(POCO_DATA_ODBC_HAVE_SQL_SERVER_EXT) && POCO_DATA_SQL_SERVER_BIG_STRINGS
+	if (Utility::dbmsName(_rStmt.connection()) == "SQLServer"s)
+		return SQL_SS_LENGTH_UNLIMITED;
+#endif
+	return columnSize;
+}
+
+
 void Binder::getColSizeAndPrecision(std::size_t pos,
 	SQLSMALLINT cDataType,
 	SQLINTEGER& colSize,
@@ -634,14 +636,14 @@ void Binder::getColumnOrParameterSize(std::size_t pos, SQLINTEGER& size)
 		ODBCMetaColumn col(_rStmt, pos);
 		colSize = col.length();
 	}
-	catch (StatementException&) { }
+	catch (StatementException&){}
 
 	try
 	{
 		Parameter p(_rStmt, pos);
 		paramSize = p.columnSize();
 	}
-	catch (StatementException&) {}
+	catch (StatementException&){}
 
 	if (colSize == 0 && paramSize == 0)
 		paramSize = getParamSizeDirect(pos, size);

Data/ODBC/src/SessionImpl.cpp

@@ -99,6 +99,12 @@ SessionImpl::~SessionImpl()
 }
 
 
+void SessionImpl::setName()
+{
+	setDBMSName(Utility::dbmsName(_db));
+}
+
+
 Poco::Data::StatementImpl::Ptr SessionImpl::createStatementImpl()
 {
 	return new ODBCStatementImpl(*this);
@@ -173,6 +179,8 @@ void SessionImpl::open(const std::string& connect)
 	else
 		throw ConnectionException(SQL_NULL_HDBC,
 			Poco::format("Connection to '%s' failed.", connectionString()));
+
+	setName();
 }
 
 

Data/ODBC/src/Utility.cpp

@@ -14,6 +14,7 @@
 
 #include "Poco/Data/ODBC/Utility.h"
 #include "Poco/Data/ODBC/Handle.h"
+#include "Poco/Data/ODBC/ConnectionHandle.h"
 #include "Poco/Data/ODBC/ODBCException.h"
 #include "Poco/NumberFormatter.h"
 #include "Poco/DateTime.h"
@@ -156,4 +157,15 @@ void Utility::dateTimeSync(SQL_TIMESTAMP_STRUCT& ts, const Poco::DateTime& dt)
 }
 
 
+std::string Utility::dbmsName(const ConnectionHandle& db)
+{
+	const SQLSMALLINT bufSize = 1024;
+	SQLCHAR dbmsName[bufSize] = {0};
+	SQLSMALLINT retSize = 0;
+	SQLRETURN rc = Poco::Data::ODBC::SQLGetInfo(const_cast<SQLHDBC>(db.handle()), SQL_DBMS_NAME, dbmsName, bufSize, &retSize);
+	if (!isError(rc)) return std::string(dbmsName[0], retSize);
+	return "unknown"s;
+}
+
+
 } } } // namespace Poco::Data::ODBC

Data/ODBC/testsuite/src/ODBCTestSuite.cpp

@@ -37,9 +37,8 @@ CppUnit::Test* ODBCTestSuite::suite()
 	//
 	// For the time being, the workaround is to connect to DB2 after connecting to PostgreSQL and Oracle.
 
-
-	addTest(pSuite, ODBCSQLServerTest::suite());
 	addTest(pSuite, ODBCOracleTest::suite());
+	addTest(pSuite, ODBCSQLServerTest::suite());
 	addTest(pSuite, ODBCMySQLTest::suite());
 	addTest(pSuite, ODBCPostgreSQLTest::suite());
 	addTest(pSuite, ODBCSQLiteTest::suite());

Data/PostgreSQL/include/Poco/Data/PostgreSQL/SessionImpl.h

@@ -130,6 +130,8 @@ class PostgreSQL_API SessionImpl: public Poco::Data::AbstractSessionImpl<Session
 	const std::string& connectorName() const;
 		/// Returns the name of the connector.
 
+	void setName();
+
 private:
 	std::string	          _connectorName;
 	mutable SessionHandle _sessionHandle;

Data/PostgreSQL/src/SessionImpl.cpp

@@ -79,6 +79,12 @@ SessionImpl::~SessionImpl()
 }
 
 
+void SessionImpl::setName()
+{
+	setDBMSName("PostgreSQL"s);
+}
+
+
 void SessionImpl::setConnectionTimeout(std::size_t aTimeout)
 {
 	_timeout = aTimeout;
@@ -145,6 +151,8 @@ void SessionImpl::open(const std::string& aConnectionString)
 	addFeature("binaryExtraction",
 		&SessionImpl::setBinaryExtraction,
 		&SessionImpl::isBinaryExtraction);
+
+	setName();
 }
 
 

Data/SQLite/include/Poco/Data/SQLite/SessionImpl.h

@@ -139,7 +139,10 @@ class SQLite_API SessionImpl: public Poco::Data::AbstractSessionImpl<SessionImpl
 
 	void setTransactionType(const std::string &prop, const Poco::Any& value);
 	Poco::Any getTransactionType(const std::string& prop) const;
+
 private:
+	void setName();
+
 	std::string _connector;
 	sqlite3*    _pDB;
 	bool        _connected;

Data/SQLite/src/SessionImpl.cpp

@@ -82,6 +82,12 @@ SessionImpl::~SessionImpl()
 }
 
 
+void SessionImpl::setName()
+{
+	setDBMSName("SQLite"s);
+}
+
+
 Poco::Data::StatementImpl::Ptr SessionImpl::createStatementImpl()
 {
 	poco_check_ptr (_pDB);
@@ -273,17 +279,17 @@ Poco::Any SessionImpl::getConnectionTimeout(const std::string& prop) const
 	return Poco::Any(_timeout/1000);
 }
 
-void SessionImpl::setTransactionType(TransactionType transactionType) 
+void SessionImpl::setTransactionType(TransactionType transactionType)
 {
 	_transactionType = transactionType;
 }
 
-void SessionImpl::setTransactionType(const std::string &prop, const Poco::Any& value) 
+void SessionImpl::setTransactionType(const std::string &prop, const Poco::Any& value)
 {
 	setTransactionType(Poco::RefAnyCast<TransactionType>(value));
 }
 
-Poco::Any SessionImpl::getTransactionType(const std::string& prop) const 
+Poco::Any SessionImpl::getTransactionType(const std::string& prop) const
 {
 	return Poco::Any(_transactionType);
 }

Data/include/Poco/Data/Session.h

@@ -204,6 +204,11 @@ class Data_API Session
 		return (_statementCreator << t);
 	}
 
+	const std::string& dbmsName() const;
+		/// Returns the DBMS name. The name must be set by the
+		/// implementation.
+		/// Defaults to "unknown".
+
 	SharedPtr<StatementImpl> createStatementImpl();
 		/// Creates a StatementImpl.
 
@@ -351,6 +356,12 @@ class Data_API Session
 // inlines
 //
 
+inline const std::string& Session::dbmsName() const
+{
+	return _pImpl->dbmsName();
+}
+
+
 inline bool Session::isAutocommit() const
 {
 	return _pImpl->isAutocommit();

Data/include/Poco/Data/SessionImpl.h

@@ -65,6 +65,11 @@ class Data_API SessionImpl: public Poco::RefCountedObject
 	virtual ~SessionImpl();
 		/// Destroys the SessionImpl.
 
+	const std::string& dbmsName() const;
+		/// Returns the DBMS name. The name must be set by the
+		/// implementation.
+		/// Defaults to "unknown".
+
 	virtual Poco::SharedPtr<StatementImpl> createStatementImpl() = 0;
 		/// Creates a StatementImpl.
 
@@ -195,6 +200,9 @@ class Data_API SessionImpl: public Poco::RefCountedObject
 		/// not supported by the underlying implementation.
 
 protected:
+	void setDBMSName(const std::string& name);
+		/// Sets the DBMS name.
+
 	void setConnectionString(const std::string& connectionString);
 		/// Sets the connection string. Should only be called on
 		/// disconnected sessions. Throws InvalidAccessException when called on
@@ -205,6 +213,7 @@ class Data_API SessionImpl: public Poco::RefCountedObject
 	SessionImpl(const SessionImpl&);
 	SessionImpl& operator = (const SessionImpl&);
 
+	std::string _dbmsName;
 	std::string _connectionString;
 	std::size_t _loginTimeout;
 };
@@ -213,6 +222,19 @@ class Data_API SessionImpl: public Poco::RefCountedObject
 //
 // inlines
 //
+
+inline void SessionImpl::setDBMSName(const std::string& name)
+{
+	_dbmsName = name;
+}
+
+
+inline const std::string& SessionImpl::dbmsName() const
+{
+	return _dbmsName;
+}
+
+
 inline const std::string& SessionImpl::connectionString() const
 {
 	return _connectionString;

Data/src/SessionImpl.cpp

@@ -21,6 +21,7 @@ namespace Data {
 
 
 SessionImpl::SessionImpl(const std::string& connectionString, std::size_t timeout):
+	_dbmsName("unknown"s),
 	_connectionString(connectionString),
 	_loginTimeout(timeout)
 {