Contributed to the apache/doris repository by enhancing the Nereids SQL Parser to support the START TRANSACTION command as a no-op, addressing compatibility for workflows referencing transactional statements. The implementation involved adding a dedicated handler in Groovy and Java that recognizes the command but performs no action, ensuring stability without introducing unsupported transactional behavior. Comprehensive regression tests were developed to validate the no-op semantics and prevent future regressions, reinforcing the reliability of transaction-related parsing. This work aligned with project standards for command handling, SQL parsing, and testing, and established a foundation for future transactional features within the Nereids engine.