Find answers from the community

Updated 9 months ago

Sql

Please, could someone explain to me how the NLSQLTableQueryEngine works on the backend? Specially interested in understanding how the schema is generated, what it looks like and what checks it does to build the SQL query. It does a quite good job. Better understanding it would help to ensure it writes usable queries.

4 comments

LLogan M

It looks at the extracted table schema and user query, and asks the llm to write its own sql query to answer the user

LLogan M

Here's the prompt if you are curious
https://github.com/run-llama/llama_index/blob/5c53f41712785e5558156372bdc4f33a6326fa5f/llama-index-core/llama_index/core/prompts/default_prompts.py#L188

LLogan M

Here's how the schema is extracted
https://github.com/run-llama/llama_index/blob/5c53f41712785e5558156372bdc4f33a6326fa5f/llama-index-core/llama_index/core/utilities/sql_wrapper.py#L150

jjpd0c

Thanks @Logan M I was playing with this. If I am honest I thought it must be doing something more. I was trying to do my own implementation with DSPy so that I can evolve it to do more complex reasoning (like Chain of Tables). But I got much lower performance with DSPy than Llamaindex (same llm, same prompt). I don't understand why.

Add a reply