try to fix return

app.py

@@ -43,27 +43,33 @@ def query_sql(user_query: str) -> str:
     Returns:
         The query result from the database as a formatted string.
     """
-    # Generate SQL from natural language
-    generated_sql = agent.run(f"Convert this request into SQL: {user_query}")
+    # Provide the AI with the correct schema
+    schema_info = (
+        "The database has a table named 'receipts' with the following schema:\n"
+        "- receipt_id (INTEGER, primary key)\n"
+        "- customer_name (VARCHAR(16))\n"
+        "- price (FLOAT)\n"
+        "- tip (FLOAT)\n"
+        "Generate an SQL query using ONLY these column names.\n"
+    )
+
+    # Generate SQL query using the provided schema
+    generated_sql = agent.run(f"{schema_info} Convert this request into SQL: {user_query}")
 
     # Log the generated SQL for debugging
     print(f"Generated SQL: {generated_sql}")
 
-    # Ensure we only execute valid SQL queries
-    if not generated_sql.lower().startswith(("select", "show", "pragma")):
+    # Ensure we only execute valid SELECT queries
+    if not generated_sql.strip().lower().startswith(("select", "show", "pragma")):
         return "Error: Only SELECT queries are allowed."
 
     # Execute the SQL query and return the result
     result = sql_engine(generated_sql)
 
-    # Log the result for debugging
+    # Log the SQL query result
     print(f"SQL Query Result: {result}")
 
-    # If the result is empty, return a friendly message
-    if not result.strip():
-        return "No results found."
-
-    return result  # Return clean result, avoiding passing raw SQL back
+    return result 
 
 # Initialize CodeAgent to generate SQL queries from natural language
 agent = CodeAgent(