Add SQL dialect support to StatementOptions

Add dialect getter/setter to StatementOptions with SQL_DIALECT_CURRENT
as the default, preserving backward compatibility.

Uses options.getDialect() in Statement constructor instead of the
hardcoded SQL_DIALECT_CURRENT constant.

Closes #42 (REQ-1).

Author: fdcastel

src/fb-cpp/Statement.cpp

@@ -51,7 +51,7 @@ Statement::Statement(
 		flags |= fb::IStatement::PREPARE_PREFETCH_DETAILED_PLAN;
 
 	statementHandle.reset(attachment.getHandle()->prepare(&statusWrapper, transaction.getHandle().get(),
-		static_cast<unsigned>(sql.length()), sql.data(), SQL_DIALECT_CURRENT, flags));
+		static_cast<unsigned>(sql.length()), sql.data(), options.getDialect(), flags));
 
 	if (options.getCursorName().has_value())
 		statementHandle->setCursorName(&statusWrapper, options.getCursorName()->c_str());

src/fb-cpp/Statement.h

@@ -164,11 +164,31 @@ namespace fbcpp
 			return *this;
 		}
 
+		///
+		/// @brief Returns the SQL dialect used when preparing the statement.
+		///
+		unsigned getDialect() const
+		{
+			return dialect;
+		}
+
+		///
+		/// @brief Sets the SQL dialect used when preparing the statement.
+		/// @param value SQL dialect number (1 for InterBase compatibility, 3 for current).
+		/// @return Reference to this instance for fluent configuration.
+		///
+		StatementOptions& setDialect(unsigned value)
+		{
+			dialect = value;
+			return *this;
+		}
+
 	private:
 		bool prefetchLegacyPlan = false;
 		bool prefetchPlan = false;
 		std::optional<std::string> cursorName;
 		CursorType cursorType = CursorType::FORWARD_ONLY;
+		unsigned dialect = SQL_DIALECT_CURRENT;
 	};
 
 	///

src/test/Statement.cpp

@@ -158,6 +158,35 @@ BOOST_AUTO_TEST_CASE(unsupportedStatementsThrow)
 	BOOST_CHECK_THROW(Statement(attachment, transaction, "rollback"), FbCppException);
 }
 
+BOOST_AUTO_TEST_CASE(dialectDefaultIsCurrent)
+{
+	StatementOptions options;
+	BOOST_CHECK_EQUAL(options.getDialect(), SQL_DIALECT_CURRENT);
+}
+
+BOOST_AUTO_TEST_CASE(dialectSetterGetter)
+{
+	StatementOptions options;
+	options.setDialect(1u);
+	BOOST_CHECK_EQUAL(options.getDialect(), 1u);
+}
+
+BOOST_AUTO_TEST_CASE(constructorWithExplicitDialect)
+{
+	const auto database = getTempFile("Statement-constructorWithExplicitDialect.fdb");
+
+	Attachment attachment{CLIENT, database, AttachmentOptions().setCreateDatabase(true)};
+	FbDropDatabase attachmentDrop{attachment};
+
+	Transaction transaction{attachment};
+	Statement stmt{
+		attachment, transaction, "select 1 from rdb$database", StatementOptions().setDialect(SQL_DIALECT_CURRENT)};
+
+	BOOST_CHECK(stmt.isValid());
+	BOOST_CHECK(stmt.execute(transaction));
+	BOOST_CHECK_EQUAL(stmt.getInt32(0).value(), 1);
+}
+
 BOOST_AUTO_TEST_SUITE_END()