How to fix Gemini API SQL query formatting issues in Langchain

[RunningTiger]

I’m having trouble with different API responses when generating SQL queries

When I use OpenAI’s API, everything works perfectly and I get clean SQL output like this:

print(generated_sql)
'SELECT COUNT(*) FROM EMPLOYEE_DATA;'

But when I switch to Gemini API, the output includes extra formatting that breaks my code:

print(generated_sql)
'```sql\nSELECT COUNT(*) AS "total_rows"\nFROM EMPLOYEE_DATA;\n```'

This formatted output causes problems when I try to execute the query:

from langchain_community.tools.sql_database.tool import QuerySQLDataBaseTool
query_tool = QuerySQLDataBaseTool(db=database)
query_tool.invoke(generated_sql)

The extra backticks and formatting characters make the query fail. Is there a simple way to strip out the markdown formatting and get just the raw SQL statement? I need the output to be clean like the OpenAI version.

[Sky24]

I’ve hit this exact problem switching between LLM providers. Gemini wraps code in markdown by default - great for reading, terrible for execution.

Quick fix: add a cleaning function before your tool runs. Strip the markdown with regex:

import re

def clean_sql_output(sql_string):
cleaned = re.sub(r’sql\n|\n|```', ‘’, sql_string)
return cleaned.strip()

generated_sql = clean_sql_output(generated_sql)
query_tool.invoke(generated_sql)

Or just change your prompt. Add “Return only the SQL query without markdown formatting or code blocks” to your template. Usually works with Gemini.

[bellagarcia]

yeah, gemini puts sql in markdown, just use generated_sql.strip('```sql').strip('```').strip() to clean it up b4 your query tool. works for me every time, hope it helps!