CSC-SQL: Corrective Self-Consistency in Text-to-SQL via Reinforcement Learning

Lei Sheng, Xu Shuai Shuai


Abstract
Large language models (LLMs) have demonstrated strong capabilities in translating natural language questions about relational databases into SQL queries. In particular, test-time scaling techniques such as Self-Consistency and Self-Correction can enhance SQL generation accuracy by increasing computational effort during inference. However, these methods have notable limitations: Self-Consistency may select suboptimal outputs despite majority votes, while Self-Correction typically addresses only syntactic errors. To leverage the strengths of both approaches, we propose CSC-SQL, a novel method that integrates Self-Consistency and Self-Correction. CSC-SQL selects the two most frequently occurring outputs from parallel sampling and feeds them into a merge revision model for correction. Additionally, we employ the Group Relative Policy Optimization (GRPO) algorithm to fine-tune both the SQL generation and revision models via reinforcement learning, significantly enhancing output quality. Experimental results confirm the effectiveness and generalizability of CSC-SQL. On the BIRD private test set, our 7B model achieves 71.72% execution accuracy, while the 32B model achieves 73.67%, outperforming other known methods using open source models. The code has been open sourced at https://github.com/CycloneBoy/csc_sql.
Anthology ID:
2025.findings-ijcnlp.91
Volume:
Proceedings of the 14th International Joint Conference on Natural Language Processing and the 4th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics
Month:
December
Year:
2025
Address:
Mumbai, India
Editors:
Kentaro Inui, Sakriani Sakti, Haofen Wang, Derek F. Wong, Pushpak Bhattacharyya, Biplab Banerjee, Asif Ekbal, Tanmoy Chakraborty, Dhirendra Pratap Singh
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Findings
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Publisher:
The Asian Federation of Natural Language Processing and The Association for Computational Linguistics
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Pages:
1473–1496
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https://preview.aclanthology.org/ingest-ijcnlp-aacl/2025.findings-ijcnlp.91/
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Cite (ACL):
Lei Sheng and Xu Shuai Shuai. 2025. CSC-SQL: Corrective Self-Consistency in Text-to-SQL via Reinforcement Learning. In Proceedings of the 14th International Joint Conference on Natural Language Processing and the 4th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics, pages 1473–1496, Mumbai, India. The Asian Federation of Natural Language Processing and The Association for Computational Linguistics.
Cite (Informal):
CSC-SQL: Corrective Self-Consistency in Text-to-SQL via Reinforcement Learning (Sheng & Shuai, Findings 2025)
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https://preview.aclanthology.org/ingest-ijcnlp-aacl/2025.findings-ijcnlp.91.pdf