feat(core): Support simple DB query for sdk (#917)

Co-authored-by: chengfangyin2 <chengfangyin3@jd.com>

dbgpt/datasource/base.py

@@ -2,58 +2,104 @@
 # -*- coding:utf-8 -*-
 
 """We need to design a base class.  That other connector can Write with this"""
-from abc import ABC, abstractmethod
-from typing import Any, Iterable, List, Optional
+from abc import ABC
+from typing import Iterable, List, Optional
 
 
 class BaseConnect(ABC):
-    def get_connect(self, db_name: str):
-        pass
-
     def get_table_names(self) -> Iterable[str]:
+        """Get all table names"""
         pass
 
     def get_table_info(self, table_names: Optional[List[str]] = None) -> str:
+        """Get table info about specified table.
+
+        Returns:
+            str: Table information joined by '\n\n'
+        """
         pass
 
     def get_index_info(self, table_names: Optional[List[str]] = None) -> str:
+        """Get index info about specified table.
+
+        Args:
+             table_names (Optional[List[str]]): table names
+        """
         pass
 
     def get_example_data(self, table: str, count: int = 3):
+        """Get example data about specified table.
+
+        Not used now.
+
+        Args:
+            table (str): table name
+            count (int): example data count
+        """
         pass
 
-    def get_database_list(self):
+    def get_database_list(self) -> List[str]:
+        """Get database list.
+
+        Returns:
+            List[str]: database list
+        """
         pass
 
     def get_database_names(self):
+        """Get database names."""
         pass
 
     def get_table_comments(self, db_name):
+        """Get table comments.
+
+        Args:
+            db_name (str): database name
+        """
         pass
 
-    def run(self, session, command: str, fetch: str = "all") -> List:
+    def run(self, command: str, fetch: str = "all") -> List:
+        """Execute sql command.
+
+        Args:
+            command (str): sql command
+            fetch (str): fetch type
+        """
         pass
 
     def run_to_df(self, command: str, fetch: str = "all"):
+        """Execute sql command and return dataframe."""
         pass
 
     def get_users(self):
-        pass
+        """Get user info."""
+        return []
 
     def get_grants(self):
-        pass
+        """Get grant info."""
+        return []
 
     def get_collation(self):
-        pass
+        """Get collation."""
+        return None
 
-    def get_charset(self):
-        pass
+    def get_charset(self) -> str:
+        """Get character_set of current database."""
+        return "utf-8"
 
     def get_fields(self, table_name):
+        """Get column fields about specified table."""
         pass
 
     def get_show_create_table(self, table_name):
+        """Get the creation table sql about specified table."""
         pass
 
     def get_indexes(self, table_name):
+        """Get table indexes about specified table."""
         pass
+
+    @classmethod
+    def is_normal_type(cls) -> bool:
+        """Return whether the connector is a normal type."""
+        return True