Streamline show table (#907)

Co-authored-by: Philipp Rudiger <prudiger@anaconda.com>

lumen/ai/agents.py

@@ -459,16 +459,26 @@ class SQLAgent(LumenBaseAgent):
 
     _output_type = SQLOutput
 
-    async def _select_relevant_table(self, messages: list[Message]) -> tuple[str, BaseSQLSource]:
+    async def _select_relevant_table(self, messages: list[Message]) -> tuple[str, BaseSQLSource, bool]:
         """Select the most relevant table based on the user query."""
+        join_required = None
         sources = self._memory["sources"]
         tables_to_source, tables_schema_str = await gather_table_sources(sources)
         tables = tuple(tables_to_source)
-        if messages and messages[-1]["content"].startswith("Show the table: '"):
+
+        user_message = ""
+        for message in messages[::-1]:
+            if message["role"] == "user":
+                user_message = message["content"]
+                break
+
+        if messages and "Show the table: " in user_message:
             # Handle the case where explicitly requested a table
-            table = re.search(r"Show the table: '([^']+)'", messages[-1]["content"]).group(1)
+            table = re.search(r"Show the table: '([^']+)'", user_message).group(1)
+            join_required = False
         elif len(tables) == 1:
             table = tables[0]
+            join_required = False
         else:
             with self.interface.add_step(title="Choosing the most relevant table...", steps_layout=self._steps_layout) as step:
                 if len(tables) > 1:
@@ -499,7 +509,7 @@ async def _select_relevant_table(self, messages: list[Message]) -> tuple[str, Ba
             sources = [src for src in sources if table in src]
             source = sources[0] if sources else self._memory["source"]
 
-        return table, source
+        return table, source, join_required
 
     @retry_llm_output()
     async def _create_valid_sql(
@@ -690,19 +700,21 @@ async def respond(
         8. If a join is required, remove source/table prefixes from the last message.
         9. Construct the SQL query with `_create_valid_sql`.
         """
-        table, source = await self._select_relevant_table(messages)
+        table, source, join_required = await self._select_relevant_table(messages)
         if not hasattr(source, "get_sql_expr"):
             return None
 
         # include min max for more context for data cleaning
         schema = await get_schema(source, table, include_min_max=True)
-        join_required = await self._check_requires_joins(messages, schema, table)
+
+        tables_to_source = {table: source}
         if join_required is None:
-            return None
-        if join_required:
-            tables_to_source = await self.find_join_tables(messages)
-        else:
-            tables_to_source = {table: source}
+            join_required = await self._check_requires_joins(messages, schema, table)
+            if join_required is None:
+                # Bail if query was cancelled or errored out
+                return None
+            if join_required:
+                tables_to_source = await self.find_join_tables(messages)
 
         tables_sql_schemas = {}
         for source_table, source in tables_to_source.items():