Add API to allow SQLite types to be added at runtime

- new types can be added via Poco::Data::SQLite::Utility::addColumnType()

issue-1375

Data/SQLite/include/Poco/Data/SQLite/Utility.h

@@ -56,6 +56,15 @@ public:
 	static const int OPERATION_DELETE;
 	static const int OPERATION_UPDATE;
 
+	static void addColumnType(std::string sqliteType, MetaColumn::ColumnDataType pocoType);
+		/// Adds or replaces the mapping for SQLite column type \p sqliteType 
+		/// to a Poco type \p pocoType
+		/// 
+		/// \p sqliteType is a case-insensitive desription of the column type with
+		/// any value \p pocoType value but MetaColumn::FDT_UNKNOWN. A
+ 		/// Poco::Data::NotSupportedException is thrown if \p pocoType is invalid.
+
+
 	static sqlite3* dbHandle(const Session& session);
 		/// Returns native DB handle.
 
@@ -190,6 +199,8 @@ private:
 	Utility(const Utility&);
 	Utility& operator = (const Utility&);
 
+	static void initializeDefaultTypes();
+
 	static void* eventHookRegister(sqlite3* pDB, UpdateCallbackType callbackFn, void* pParam);
 	static void* eventHookRegister(sqlite3* pDB, CommitCallbackType callbackFn, void* pParam);
 	static void* eventHookRegister(sqlite3* pDB, RollbackCallbackType callbackFn, void* pParam);

Data/SQLite/src/Utility.cpp

@@ -62,6 +62,11 @@ Poco::Mutex Utility::_mutex;
 
 
 Utility::Utility()
+{
+	initializeDefaultTypes();
+}
+
+void Utility::initializeDefaultTypes()
 {
 	if (_types.empty())
 	{
@@ -125,6 +130,21 @@ Utility::Utility()
 }
 
 
+void Utility::addColumnType(std::string sqliteType, MetaColumn::ColumnDataType pocoType)
+{
+	// Check for errors in the mapping
+	if (MetaColumn::FDT_UNKNOWN == pocoType)
+		throw Poco::Data::NotSupportedException("Cannot map to unknown poco type.");
+
+	// Initialize default types
+	initializeDefaultTypes();
+
+	// Add type to internal map
+	Poco::toUpperInPlace(sqliteType);
+	_types[sqliteType] = pocoType;
+}
+
+
 std::string Utility::lastError(sqlite3* pDB)
 {
 	return std::string(sqlite3_errmsg(pDB));