diff --git a/danding_bot/plugins/danding_points/api.py b/danding_bot/plugins/danding_points/api.py
index f514b4e..02ff879 100644
--- a/danding_bot/plugins/danding_points/api.py
+++ b/danding_bot/plugins/danding_points/api.py
@@ -59,6 +59,7 @@ class PointsAPI:
                     new_balance = current_balance + amount
                     if self.config.POINTS_MAX_BALANCE > 0:
                         if new_balance > self.config.POINTS_MAX_BALANCE:
+                            conn.rollback()
                             conn.close()
                             return False, current_balance
 
@@ -130,6 +131,7 @@ class PointsAPI:
 
                     # Check sufficient balance
                     if current_balance < amount:
+                        conn.rollback()
                         conn.close()
                         return False, current_balance
 
@@ -198,6 +200,7 @@ class PointsAPI:
 
                     # If new value equals old value, return without writing
                     if current_balance == amount:
+                        conn.rollback()
                         conn.close()
                         return True, amount
 
@@ -250,20 +253,25 @@ class PointsAPI:
 
         def _get():
             conn = self.db.get_connection()
-            cursor = conn.cursor()
-            cursor.execute(
-                """
-                SELECT id, user_id, amount, balance_after, source, reason, created_at
-                FROM point_transactions
-                WHERE user_id = ?
-                ORDER BY id DESC
-                LIMIT ? OFFSET ?
-                """,
-                (user_id, limit, offset),
-            )
-            rows = cursor.fetchall()
-            conn.close()
-            return [dict(row) for row in rows]
+            try:
+                cursor = conn.cursor()
+                cursor.execute(
+                    """
+                    SELECT id, user_id, amount, balance_after, source, reason, created_at
+                    FROM point_transactions
+                    WHERE user_id = ?
+                    ORDER BY id DESC
+                    LIMIT ? OFFSET ?
+                    """,
+                    (user_id, limit, offset),
+                )
+                rows = cursor.fetchall()
+                return [dict(row) for row in rows]
+            except Exception as e:
+                logger.error(f"get_transactions failed for {user_id}: {e}")
+                return []
+            finally:
+                conn.close()
 
         return await asyncio.to_thread(_get)
 
@@ -281,23 +289,27 @@ class PointsAPI:
 
         def _get():
             conn = self.db.get_connection()
-            cursor = conn.cursor()
-
-            order_column = "points" if order_by == "points" else "total_earned"
-            query = f"""
-                SELECT
-                    RANK() OVER (ORDER BY {order_column} DESC) as rank,
-                    user_id,
-                    points,
-                    total_earned,
-                    total_spent
-                FROM user_points
-                ORDER BY {order_column} DESC, user_id ASC
-                LIMIT ?
-            """
-            cursor.execute(query, (limit,))
-            rows = cursor.fetchall()
-            conn.close()
-            return [dict(row) for row in rows]
+            try:
+                cursor = conn.cursor()
+                order_column = "points" if order_by == "points" else "total_earned"
+                query = f"""
+                    SELECT
+                        RANK() OVER (ORDER BY {order_column} DESC) as rank,
+                        user_id,
+                        points,
+                        total_earned,
+                        total_spent
+                    FROM user_points
+                    ORDER BY {order_column} DESC, user_id ASC
+                    LIMIT ?
+                """
+                cursor.execute(query, (limit,))
+                rows = cursor.fetchall()
+                return [dict(row) for row in rows]
+            except Exception as e:
+                logger.error(f"get_ranking failed: {e}")
+                return []
+            finally:
+                conn.close()
 
         return await asyncio.to_thread(_get)