refactor: The first refactored version for sdk release (#907)

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

dbgpt/datasource/rdbms/conn_duckdb.py

@@ -0,0 +1,79 @@
+from typing import Optional, Any, Iterable
+from sqlalchemy import (
+    create_engine,
+    text,
+)
+
+from dbgpt.datasource.rdbms.base import RDBMSDatabase
+
+
+class DuckDbConnect(RDBMSDatabase):
+    """Connect Duckdb Database fetch MetaData
+    Args:
+    Usage:
+    """
+
+    db_type: str = "duckdb"
+    db_dialect: str = "duckdb"
+
+    @classmethod
+    def from_file_path(
+        cls, file_path: str, engine_args: Optional[dict] = None, **kwargs: Any
+    ) -> RDBMSDatabase:
+        """Construct a SQLAlchemy engine from URI."""
+        _engine_args = engine_args or {}
+        return cls(create_engine("duckdb:///" + file_path, **_engine_args), **kwargs)
+
+    def get_users(self):
+        cursor = self.session.execute(
+            text(
+                f"SELECT * FROM sqlite_master WHERE type = 'table' AND name = 'duckdb_sys_users';"
+            )
+        )
+        users = cursor.fetchall()
+        return [(user[0], user[1]) for user in users]
+
+    def get_grants(self):
+        return []
+
+    def get_collation(self):
+        """Get collation."""
+        return "UTF-8"
+
+    def get_charset(self):
+        return "UTF-8"
+
+    def get_table_comments(self, db_name):
+        cursor = self.session.execute(
+            text(
+                f"""
+                SELECT name, sql FROM sqlite_master WHERE type='table'
+                """
+            )
+        )
+        table_comments = cursor.fetchall()
+        return [
+            (table_comment[0], table_comment[1]) for table_comment in table_comments
+        ]
+
+    def table_simple_info(self) -> Iterable[str]:
+        _tables_sql = f"""
+                SELECT name FROM sqlite_master WHERE type='table'
+            """
+        cursor = self.session.execute(text(_tables_sql))
+        tables_results = cursor.fetchall()
+        results = []
+        for row in tables_results:
+            table_name = row[0]
+            _sql = f"""
+                PRAGMA  table_info({table_name})
+            """
+            cursor_colums = self.session.execute(text(_sql))
+            colum_results = cursor_colums.fetchall()
+            table_colums = []
+            for row_col in colum_results:
+                field_info = list(row_col)
+                table_colums.append(field_info[1])
+
+            results.append(f"{table_name}({','.join(table_colums)});")
+        return results