--- library_name: transformers license: cc-by-nc-4.0 pipeline_tag: text-generation tags: - text-to-sql - reinforcement-learning --- # SLM-SQL: An Exploration of Small Language Models for Text-to-SQL ### Important Links 📖[Paper](https://arxiv.org/abs/2507.22478) | 💻[GitHub](https://github.com/CycloneBoy/slm_sql) | 🤗[HuggingFace Collection](https://huggingface.co/collections/cycloneboy/slm-sql-688b02f99f958d7a417658dc) | 🤖[ModelScope Collection](https://modelscope.cn/collections/SLM-SQL-624bb6a60e9643) | ## News + `July 31, 2025`: Upload model to modelscope and huggingface. + `July 30, 2025`: Publish the paper to arxiv ## Introduction Large language models (LLMs) have demonstrated strong performance in translating natural language questions into SQL queries (Text-to-SQL). In contrast, small language models (SLMs) ranging from 0.5B to 1.5B parameters currently underperform on Text-to-SQL tasks due to their limited logical reasoning capabilities. However, SLMs offer inherent advantages in inference speed and suitability for edge deployment. To explore their potential in Text-to-SQL applications, we leverage recent advancements in post-training techniques. Specifically, we used the open-source SynSQL-2.5M dataset to construct two derived datasets: SynSQL-Think-916K for SQL generation and SynSQL-Merge-Think-310K for SQL merge revision. We then applied supervised fine-tuning and reinforcement learning-based post-training to the SLM, followed by inference using a corrective self-consistency approach. Experimental results validate the effectiveness and generalizability of our method, SLM-SQL. On the BIRD development set, the five evaluated models achieved an average improvement of 31.4 points. Notably, the 0.5B model reached 56.87\% execution accuracy (EX), while the 1.5B model achieved 67.08\% EX. ### Framework slmsql_framework ### Main Results slm_sql_result slmsql_bird_main slmsql_spider_main Performance Comparison of different Text-to-SQL methods on BIRD dev and test dataset. slmsql_ablation_study ## Model | **Model** | Base Model | Train Method | Modelscope | HuggingFace | |------------------------------------------|------------------------------|--------------|---------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------| | SLM-SQL-Base-0.5B | Qwen2.5-Coder-0.5B-Instruct | SFT | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/SLM-SQL-Base-0.5B) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/SLM-SQL-Base-0.5B) | | SLM-SQL-0.5B | Qwen2.5-Coder-0.5B-Instruct | SFT + GRPO | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/SLM-SQL-0.5B) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/SLM-SQL-0.5B) | | CscSQL-Merge-Qwen2.5-Coder-0.5B-Instruct | Qwen2.5-Coder-0.5B-Instruct | SFT + GRPO | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/CscSQL-Merge-Qwen2.5-Coder-0.5B-Instruct) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/CscSQL-Merge-Qwen2.5-Coder-0.5B-Instruct) | | SLM-SQL-Base-1.5B | Qwen2.5-Coder-1.5B-Instruct | SFT | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/SLM-SQL-Base-1.5B) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/SLM-SQL-Base-1.5B) |\ | SLM-SQL-1.5B | Qwen2.5-Coder-1.5B-Instruct | SFT + GRPO | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/SLM-SQL-1.5B) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/SLM-SQL-1.5B) | | CscSQL-Merge-Qwen2.5-Coder-1.5B-Instruct | Qwen2.5-Coder-1.5B-Instruct | SFT + GRPO | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/CscSQL-Merge-Qwen2.5-Coder-1.5B-Instruct) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/CscSQL-Merge-Qwen2.5-Coder-1.5B-Instruct) | | SLM-SQL-Base-0.6B | Qwen3-0.6B | SFT | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/SLM-SQL-Base-0.6B) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/SLM-SQL-Base-0.6B) | | SLM-SQL-0.6B | Qwen3-0.6B | SFT + GRPO | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/SLM-SQL-0.6B) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/SLM-SQL-0.6B) | | SLM-SQL-Base-1.3B | deepseek-coder-1.3b-instruct | SFT | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/SLM-SQL-Base-1.3B ) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/SLM-SQL-Base-1.3B ) | | SLM-SQL-1.3B | deepseek-coder-1.3b-instruct | SFT + GRPO | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/SLM-SQL-1.3B ) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/SLM-SQL-1.3B ) | | SLM-SQL-Base-1B | Llama-3.2-1B-Instruct | SFT | [🤖 Modelscope](https://modelscope.cn/models/cycloneboy/SLM-SQL-Base-1B ) | [🤗 HuggingFace](https://huggingface.co/cycloneboy/SLM-SQL-Base-1B ) | ## Sample Usage This model can be easily loaded and used with the `transformers` library. The following example demonstrates how to perform Text-to-SQL generation. ```python import torch from transformers import AutoTokenizer, AutoModelForCausalLM model_id = "cycloneboy/SLM-SQL-0.5B" # You can choose any of the models from the table above tokenizer = AutoTokenizer.from_pretrained(model_id) model = AutoModelForCausalLM.from_pretrained( model_id, torch_dtype=torch.bfloat16, # Use torch.bfloat16 as specified in the model's config device_map="auto" # Automatically maps the model to available devices (e.g., GPU) ) # Example SQL schema (simplified for demonstration) schema = """ CREATE TABLE employees ( employee_id INT, first_name VARCHAR, last_name VARCHAR, department VARCHAR, salary INT ); """ # Natural language query query = "Show me the first name and last name of employees in the 'Sales' department earning more than 50000." # Construct the prompt using the model's chat template format # The chat template automatically adds system/user tags if available. messages = [ {"role": "user", "content": f"Translate the following natural language query into SQL:\ Schema: {schema}\ Query: {query}"} ] prompt_text = tokenizer.apply_chat_template(messages, tokenize=False, add_generation_prompt=True) inputs = tokenizer(prompt_text, return_tensors="pt").to(model.device) # Generate the SQL query outputs = model.generate(**inputs, max_new_tokens=256, pad_token_id=tokenizer.eos_token_id) generated_text = tokenizer.decode(outputs[0], skip_special_tokens=True) # Extracting only the generated SQL part (assuming the model responds only with SQL after "### Response:") # The model's chat template is `### Instruction: ... ### Response: ...<|EOT|>` # We need to trim the input prompt and the <|EOT|> token. if "### Response:" in generated_text: sql_start_index = generated_text.find("### Response:") + len("### Response:") generated_sql = generated_text[sql_start_index:].strip() if "<|EOT|>" in generated_sql: generated_sql = generated_sql.split("<|EOT|>")[0].strip() else: generated_sql = generated_text # Fallback if response format is unexpected print(generated_sql) # Expected output (may vary slightly based on model's exact generation): # SELECT first_name, last_name FROM employees WHERE department = 'Sales' AND salary > 50000; ``` ## Dataset | **Dataset** | Modelscope | HuggingFace | |----------------------------|------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------| | SynsQL-Think-916k | [🤖 Modelscope](https://modelscope.cn/datasets/cycloneboy/SynsQL-Think-916k) | [🤗 HuggingFace](https://huggingface.co/datasets/cycloneboy/SynsQL-Think-916k) | | SynsQL-Merge-Think-310k | [🤖 Modelscope](https://modelscope.cn/datasets/cycloneboy/SynsQL-Merge-Think-310k) | [🤗 HuggingFace](https://huggingface.co/datasets/cycloneboy/SynsQL-Merge-Think-310k) | | bird train and dev dataset | [🤖 Modelscope](https://modelscope.cn/datasets/cycloneboy/bird_train) | [🤗 HuggingFace](https://huggingface.co/datasets/cycloneboy/bird_train) | ## TODO - [ ] Release inference code - [ ] Upload Model - [ ] Release training code - [ ] Fix bug - [ ] Update doc ## Thanks to the following projects - [csc_sql](https://github.com/CycloneBoy/csc_sql) - [open-r1](https://github.com/huggingface/open-r1) - [OmniSQL](https://github.com/RUCKBReasoning/OmniSQL) ## Citation ```bibtex @misc{sheng2025slmsqlexplorationsmalllanguage, title={SLM-SQL: An Exploration of Small Language Models for Text-to-SQL}, author={Lei Sheng and Shuai-Shuai Xu}, year={2025}, eprint={2507.22478}, archivePrefix={arXiv}, primaryClass={cs.CL}, url={https://arxiv.org/abs/2507.22478}, } @misc{sheng2025cscsqlcorrectiveselfconsistencytexttosql, title={CSC-SQL: Corrective Self-Consistency in Text-to-SQL via Reinforcement Learning}, author={Lei Sheng and Shuai-Shuai Xu}, year={2025}, eprint={2505.13271}, archivePrefix={arXiv}, primaryClass={cs.CL}, url={https://arxiv.org/abs/2505.13271}, } ```