feat(agent): Multi agent sdk (#976)

Co-authored-by: xtyuns <xtyuns@163.com>
Co-authored-by: Fangyin Cheng <staneyffer@gmail.com>
Co-authored-by: csunny <cfqsunny@163.com>
Co-authored-by: qidanrui <qidanrui@gmail.com>

dbgpt/datasource/rdbms/base.py

@@ -334,7 +334,7 @@ class RDBMSDatabase(BaseConnect):
         """
         print(f"Query[{query}]")
         if not query:
-            return []
+            return [], None
         cursor = self.session.execute(text(query))
         if cursor.returns_rows:
             if fetch == "all":
@@ -347,7 +347,7 @@ class RDBMSDatabase(BaseConnect):
 
             result = list(result)
             return field_names, result
-        return []
+        return [], None
 
     def run(self, command: str, fetch: str = "all") -> List:
         """Execute a SQL command and return a string representing the results."""