diff --git a/migrate_fix_signin_logs_fk.sql b/migrate_fix_signin_logs_fk.sql
index 7df3841..c1ff64c 100644
--- a/migrate_fix_signin_logs_fk.sql
+++ b/migrate_fix_signin_logs_fk.sql
@@ -1,21 +1,10 @@
--- 修复 signin_logs 外键：删除账号时级联删除签到记录
+-- 修复 signin_logs 外键
 -- 用法: mysql -u weibo -p123456 weibo_hotsign < migrate_fix_signin_logs_fk.sql
 
--- 先查出旧外键名并删除，再重建
-SET @fk_name = (
-    SELECT CONSTRAINT_NAME FROM information_schema.KEY_COLUMN_USAGE
-    WHERE TABLE_SCHEMA = 'weibo_hotsign'
-      AND TABLE_NAME = 'signin_logs'
-      AND COLUMN_NAME = 'account_id'
-      AND REFERENCED_TABLE_NAME = 'accounts'
-    LIMIT 1
-);
-
-SET @sql = CONCAT('ALTER TABLE signin_logs DROP FOREIGN KEY ', @fk_name);
-PREPARE stmt FROM @sql;
-EXECUTE stmt;
-DEALLOCATE PREPARE stmt;
+-- 1. 清理孤儿记录
+DELETE FROM signin_logs WHERE account_id NOT IN (SELECT id FROM accounts);
 
+-- 2. 重建外键（带 CASCADE），忽略已存在的情况
 ALTER TABLE signin_logs
     ADD CONSTRAINT fk_signin_logs_account
     FOREIGN KEY (account_id) REFERENCES accounts(id) ON DELETE CASCADE;