Prompt user to click Rerun if empty (#1215)

Author: ahuang11

lumen/ai/agents.py

@@ -294,6 +294,16 @@ class AnalystAgent(ChatAgent):
 
     requires = param.List(default=["source", "pipeline"], readonly=True)
 
+    async def respond(
+        self,
+        messages: list[Message],
+        render_output: bool = False,
+        step_title: str | None = None,
+    ) -> Any:
+        messages = super().respond(messages, render_output, step_title)
+        if len(self._memory["data"]) == 0 and self._memory.get("sql"):
+            self._memory["sql"] = f"{self._memory['sql']}\n-- No data was returned from the query."
+        return messages
 
 class ListAgent(Agent):
     """

lumen/ai/prompts/AnalystAgent/main.jinja2

@@ -91,7 +91,11 @@ Here was the plan that was executed:
 """
 
 Here is the current dataset:
+{% if memory.data|length == 0 %}
+The data is empty. Critique the SQL query and suggest what other columns or values should be used instead. Then prompt the user to click the rerun button below if they'd like to try again.
+{% else %}
 {{ memory.data }}
+{% endif %}
 
 {% if 'sql' in memory %}
 Here is the current SQL query: