diff --git a/app.py b/app.py
index 444adbd..1532002 100644
--- a/app.py
+++ b/app.py
@@ -16,18 +16,24 @@ app = Flask(__name__)
 logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(name)s - %(levelname)s - %(message)s')
 logger = logging.getLogger(__name__)
 
+# 数据库配置
+DATABASE_PATH = 'config_groups.db'
+
 # 查询日志收集器
 class QueryLogCollector:
-    def __init__(self, max_logs=1000):
-        self.logs = []
+    def __init__(self, max_logs=1000, db_path=None):
+        self.logs = []  # 内存中的日志缓存
         self.max_logs = max_logs
         self.current_batch_id = None
         self.batch_counter = 0
+        self.current_query_type = 'single'
+        self.db_path = db_path or DATABASE_PATH
     
     def start_new_batch(self, query_type='single'):
         """开始新的查询批次"""
         self.batch_counter += 1
         self.current_batch_id = f"batch_{self.batch_counter}_{datetime.now().strftime('%H%M%S')}"
+        self.current_query_type = query_type
         
         # 添加批次开始标记
         self.add_log('INFO', f"=== 开始{query_type}查询批次 (ID: {self.current_batch_id}) ===", force_batch_id=self.current_batch_id)
@@ -39,29 +45,114 @@ class QueryLogCollector:
             self.add_log('INFO', f"=== 查询批次完成 (ID: {self.current_batch_id}) ===", force_batch_id=self.current_batch_id)
             self.current_batch_id = None
     
-    def add_log(self, level, message, force_batch_id=None):
+    def add_log(self, level, message, force_batch_id=None, force_query_type=None):
+        """添加日志到内存和数据库"""
         timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S.%f')[:-3]
         batch_id = force_batch_id or self.current_batch_id
+        query_type = force_query_type or self.current_query_type
         
         log_entry = {
             'timestamp': timestamp,
             'level': level,
             'message': message,
-            'batch_id': batch_id
+            'batch_id': batch_id,
+            'query_type': query_type
         }
+        
+        # 添加到内存缓存
         self.logs.append(log_entry)
-        # 保持日志数量在限制内
         if len(self.logs) > self.max_logs:
             self.logs.pop(0)
+        
+        # 保存到数据库
+        self._save_log_to_db(log_entry)
     
-    def get_logs(self, limit=None):
-        if limit:
-            return self.logs[-limit:]
-        return self.logs
+    def _save_log_to_db(self, log_entry):
+        """将日志保存到数据库"""
+        try:
+            conn = sqlite3.connect(self.db_path, timeout=30)
+            cursor = conn.cursor()
+            
+            cursor.execute('''
+                INSERT INTO query_logs (batch_id, timestamp, level, message, query_type)
+                VALUES (?, ?, ?, ?, ?)
+            ''', (
+                log_entry['batch_id'],
+                log_entry['timestamp'], 
+                log_entry['level'],
+                log_entry['message'],
+                log_entry['query_type']
+            ))
+            
+            conn.commit()
+            conn.close()
+        except Exception as e:
+            # 数据库写入失败时记录到控制台，但不影响程序运行
+            print(f"Warning: Failed to save log to database: {e}")
     
-    def get_logs_grouped_by_batch(self, limit=None):
+    def get_logs(self, limit=None, from_db=True):
+        """获取日志，支持从数据库或内存获取"""
+        if from_db:
+            return self._get_logs_from_db(limit)
+        else:
+            # 从内存获取
+            if limit:
+                return self.logs[-limit:]
+            return self.logs
+    
+    def _get_logs_from_db(self, limit=None):
+        """从数据库获取日志"""
+        try:
+            conn = sqlite3.connect(self.db_path, timeout=30)
+            conn.row_factory = sqlite3.Row
+            cursor = conn.cursor()
+            
+            query = '''
+                SELECT batch_id, timestamp, level, message, query_type 
+                FROM query_logs 
+                ORDER BY id DESC
+            '''
+            
+            if limit:
+                query += f' LIMIT {limit}'
+            
+            cursor.execute(query)
+            rows = cursor.fetchall()
+            
+            # 转换为字典格式并反转顺序（最新的在前）
+            logs = []
+            for row in reversed(rows):
+                logs.append({
+                    'batch_id': row['batch_id'],
+                    'timestamp': row['timestamp'],
+                    'level': row['level'], 
+                    'message': row['message'],
+                    'query_type': row['query_type']
+                })
+            
+            conn.close()
+            return logs
+        except Exception as e:
+            print(f"Warning: Failed to get logs from database: {e}")
+            # 如果数据库读取失败，返回内存中的日志
+            return self.get_logs(limit, from_db=False)
+    
+    def _get_total_logs_count(self):
+        """获取数据库中的日志总数"""
+        try:
+            conn = sqlite3.connect(self.db_path, timeout=30)
+            cursor = conn.cursor()
+            cursor.execute('SELECT COUNT(*) FROM query_logs')
+            count = cursor.fetchone()[0]
+            conn.close()
+            return count
+        except Exception as e:
+            print(f"Warning: Failed to get logs count from database: {e}")
+            return len(self.logs)
+    
+    def get_logs_grouped_by_batch(self, limit=None, from_db=True):
         """按批次分组获取日志"""
-        logs = self.get_logs(limit)
+        logs = self.get_logs(limit, from_db)
         grouped_logs = {}
         batch_order = []
         
@@ -75,10 +166,46 @@ class QueryLogCollector:
         # 返回按时间顺序排列的批次
         return [(batch_id, grouped_logs[batch_id]) for batch_id in batch_order]
     
-    def clear_logs(self):
+    def clear_logs(self, clear_db=True):
+        """清空日志"""
+        # 清空内存
         self.logs.clear()
         self.current_batch_id = None
         self.batch_counter = 0
+        
+        # 清空数据库
+        if clear_db:
+            try:
+                conn = sqlite3.connect(self.db_path, timeout=30)
+                cursor = conn.cursor()
+                cursor.execute('DELETE FROM query_logs')
+                conn.commit()
+                conn.close()
+            except Exception as e:
+                print(f"Warning: Failed to clear logs from database: {e}")
+    
+    def cleanup_old_logs(self, days_to_keep=30):
+        """清理旧日志，保留指定天数的日志"""
+        try:
+            conn = sqlite3.connect(self.db_path, timeout=30)
+            cursor = conn.cursor()
+            
+            # 删除超过指定天数的日志
+            cutoff_date = datetime.now() - timedelta(days=days_to_keep)
+            cursor.execute('''
+                DELETE FROM query_logs 
+                WHERE created_at < ?
+            ''', (cutoff_date.strftime('%Y-%m-%d %H:%M:%S'),))
+            
+            deleted_count = cursor.rowcount
+            conn.commit()
+            conn.close()
+            
+            logger.info(f"清理了 {deleted_count} 条超过 {days_to_keep} 天的旧日志")
+            return deleted_count
+        except Exception as e:
+            logger.error(f"清理旧日志失败: {e}")
+            return 0
 
 # 全局日志收集器实例
 query_log_collector = QueryLogCollector()
@@ -96,9 +223,6 @@ class CollectorHandler(logging.Handler):
 collector_handler = CollectorHandler(query_log_collector)
 logger.addHandler(collector_handler)
 
-# 数据库配置
-DATABASE_PATH = 'config_groups.db'
-
 class ShardingCalculator:
     """分表计算器，基于TWCS策略"""
     
@@ -262,6 +386,24 @@ def init_database():
             )
         ''')
         
+        # 创建查询日志表
+        cursor.execute('''
+            CREATE TABLE IF NOT EXISTS query_logs (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                batch_id TEXT NOT NULL,
+                timestamp TEXT NOT NULL,
+                level TEXT NOT NULL,
+                message TEXT NOT NULL,
+                query_type TEXT DEFAULT 'single',
+                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+            )
+        ''')
+        
+        # 创建索引
+        cursor.execute('CREATE INDEX IF NOT EXISTS idx_query_logs_batch_id ON query_logs(batch_id)')
+        cursor.execute('CREATE INDEX IF NOT EXISTS idx_query_logs_timestamp ON query_logs(timestamp)')
+        cursor.execute('CREATE INDEX IF NOT EXISTS idx_query_logs_level ON query_logs(level)')
+        
         conn.commit()
         conn.close()
         logger.info("数据库初始化完成")
@@ -280,11 +422,11 @@ def ensure_database():
     try:
         conn = sqlite3.connect(DATABASE_PATH)
         cursor = conn.cursor()
-        cursor.execute("SELECT name FROM sqlite_master WHERE type='table' AND name IN ('config_groups', 'query_history', 'sharding_config_groups')")
+        cursor.execute("SELECT name FROM sqlite_master WHERE type='table' AND name IN ('config_groups', 'query_history', 'sharding_config_groups', 'query_logs')")
         results = cursor.fetchall()
         existing_tables = [row[0] for row in results]
         
-        required_tables = ['config_groups', 'query_history', 'sharding_config_groups']
+        required_tables = ['config_groups', 'query_history', 'sharding_config_groups', 'query_logs']
         missing_tables = [table for table in required_tables if table not in existing_tables]
         
         if missing_tables:
@@ -1776,19 +1918,34 @@ def api_get_query_history_results(history_id):
         if not history_record:
             return jsonify({'success': False, 'error': '历史记录不存在'}), 404
         
+        # 安全获取raw_results数据
+        raw_results = history_record.get('raw_results')
+        if raw_results and isinstance(raw_results, dict):
+            raw_pro_data = raw_results.get('raw_pro_data', []) or []
+            raw_test_data = raw_results.get('raw_test_data', []) or []
+            sharding_info = raw_results.get('sharding_info') if history_record.get('query_type') == 'sharding' else None
+        else:
+            raw_pro_data = []
+            raw_test_data = []
+            sharding_info = None
+            
+        # 安全获取差异和相同结果数据
+        differences_data = history_record.get('differences_data') or []
+        identical_data = history_record.get('identical_data') or []
+        
         # 构建完整的查询结果格式，与API查询结果保持一致
         result = {
             'total_keys': history_record['total_keys'],
-            'pro_count': len(history_record.get('raw_results', {}).get('raw_pro_data', [])) if history_record.get('raw_results') else 0,
-            'test_count': len(history_record.get('raw_results', {}).get('raw_test_data', [])) if history_record.get('raw_results') else 0,
-            'differences': history_record.get('differences_data', []),
-            'identical_results': history_record.get('identical_data', []),
+            'pro_count': len(raw_pro_data),
+            'test_count': len(raw_test_data),
+            'differences': differences_data,
+            'identical_results': identical_data,
             'field_diff_count': {},  # 可以从differences_data中重新计算
             'summary': history_record.get('results_summary', {}),
-            'raw_pro_data': history_record.get('raw_results', {}).get('raw_pro_data', []) if history_record.get('raw_results') else [],
-            'raw_test_data': history_record.get('raw_results', {}).get('raw_test_data', []) if history_record.get('raw_results') else [],
+            'raw_pro_data': raw_pro_data,
+            'raw_test_data': raw_test_data,
             # 如果是分表查询，添加分表信息
-            'sharding_info': history_record.get('raw_results', {}).get('sharding_info') if history_record.get('raw_results') and history_record.get('query_type') == 'sharding' else None,
+            'sharding_info': sharding_info,
             # 添加历史记录元信息
             'history_info': {
                 'id': history_record['id'],
@@ -1800,10 +1957,10 @@ def api_get_query_history_results(history_id):
         }
         
         # 重新计算field_diff_count
-        if history_record.get('differences_data'):
+        if differences_data:
             field_diff_count = {}
-            for diff in history_record['differences_data']:
-                if 'field' in diff:
+            for diff in differences_data:
+                if isinstance(diff, dict) and 'field' in diff:
                     field_name = diff['field']
                     field_diff_count[field_name] = field_diff_count.get(field_name, 0) + 1
             result['field_diff_count'] = field_diff_count
@@ -1830,28 +1987,36 @@ def api_delete_query_history(history_id):
 
 @app.route('/api/query-logs', methods=['GET'])
 def api_get_query_logs():
-    """获取查询日志，支持分组显示"""
+    """获取查询日志，支持分组显示和数据库存储"""
     try:
         limit = request.args.get('limit', type=int)
         grouped = request.args.get('grouped', 'true').lower() == 'true'  # 默认分组显示
+        from_db = request.args.get('from_db', 'true').lower() == 'true'  # 默认从数据库获取
         
         if grouped:
             # 返回分组日志
-            grouped_logs = query_log_collector.get_logs_grouped_by_batch(limit)
+            grouped_logs = query_log_collector.get_logs_grouped_by_batch(limit, from_db)
+            # 获取总数（用于统计）
+            total_logs = query_log_collector._get_total_logs_count() if from_db else len(query_log_collector.logs)
+            
             return jsonify({
                 'success': True,
                 'data': grouped_logs,
-                'total': len(query_log_collector.logs),
-                'grouped': True
+                'total': total_logs,
+                'grouped': True,
+                'from_db': from_db
             })
         else:
             # 返回原始日志列表
-            logs = query_log_collector.get_logs(limit)
+            logs = query_log_collector.get_logs(limit, from_db)
+            total_logs = query_log_collector._get_total_logs_count() if from_db else len(query_log_collector.logs)
+            
             return jsonify({
                 'success': True,
                 'data': logs,
-                'total': len(query_log_collector.logs),
-                'grouped': False
+                'total': total_logs,
+                'grouped': False,
+                'from_db': from_db
             })
     except Exception as e:
         logger.error(f"获取查询日志失败: {e}")
@@ -1859,13 +2024,32 @@ def api_get_query_logs():
 
 @app.route('/api/query-logs', methods=['DELETE'])
 def api_clear_query_logs():
-    """清空查询日志"""
+    """清空查询日志，支持清空数据库日志"""
     try:
-        query_log_collector.clear_logs()
-        return jsonify({'success': True, 'message': '查询日志已清空'})
+        clear_db = request.args.get('clear_db', 'true').lower() == 'true'  # 默认清空数据库
+        query_log_collector.clear_logs(clear_db)
+        
+        message = '查询日志已清空（包括数据库）' if clear_db else '查询日志已清空（仅内存）'
+        return jsonify({'success': True, 'message': message})
     except Exception as e:
         logger.error(f"清空查询日志失败: {e}")
         return jsonify({'success': False, 'error': str(e)}), 500
 
+@app.route('/api/query-logs/cleanup', methods=['POST'])
+def api_cleanup_old_logs():
+    """清理旧的查询日志"""
+    try:
+        days_to_keep = request.json.get('days_to_keep', 30) if request.json else 30
+        deleted_count = query_log_collector.cleanup_old_logs(days_to_keep)
+        
+        return jsonify({
+            'success': True,
+            'message': f'成功清理 {deleted_count} 条超过 {days_to_keep} 天的旧日志',
+            'deleted_count': deleted_count
+        })
+    except Exception as e:
+        logger.error(f"清理旧日志失败: {e}")
+        return jsonify({'success': False, 'error': str(e)}), 500
+
 if __name__ == '__main__':
     app.run(debug=True, port=5000)
diff --git a/static/js/app.js b/static/js/app.js
index 6bf4d3a..3814c2b 100644
--- a/static/js/app.js
+++ b/static/js/app.js
@@ -2736,8 +2736,16 @@ async function loadHistoryResults(historyId) {
             // 设置当前结果数据
             currentResults = result.data;
             
+            // 确保必要的数组字段存在
+            if (!currentResults.differences) currentResults.differences = [];
+            if (!currentResults.identical_results) currentResults.identical_results = [];
+            if (!currentResults.raw_pro_data) currentResults.raw_pro_data = [];
+            if (!currentResults.raw_test_data) currentResults.raw_test_data = [];
+            if (!currentResults.field_diff_count) currentResults.field_diff_count = {};
+            if (!currentResults.summary) currentResults.summary = {};
+            
             // 根据查询类型设置分表模式
-            if (result.data.history_info.query_type === 'sharding') {
+            if (result.data.history_info && result.data.history_info.query_type === 'sharding') {
                 isShardingMode = true;
                 document.getElementById('enableSharding').checked = true;
                 toggleShardingMode();
@@ -2752,14 +2760,18 @@ async function loadHistoryResults(historyId) {
             
             // 关闭历史记录modal
             const modal = bootstrap.Modal.getInstance(document.getElementById('queryHistoryModal'));
-            modal.hide();
+            if (modal) {
+                modal.hide();
+            }
             
-            const queryTypeDesc = result.data.history_info.query_type === 'sharding' ? '分表查询' : '单表查询';
-            showAlert('success', `${queryTypeDesc}历史记录结果 "${result.data.history_info.name}" 加载成功`);
+            const queryTypeDesc = (result.data.history_info && result.data.history_info.query_type === 'sharding') ? '分表查询' : '单表查询';
+            const historyName = (result.data.history_info && result.data.history_info.name) || '未知';
+            showAlert('success', `${queryTypeDesc}历史记录结果 "${historyName}" 加载成功`);
         } else {
             showAlert('danger', result.error || '加载历史记录结果失败');
         }
     } catch (error) {
+        console.error('加载历史记录结果失败:', error);
         showAlert('danger', '加载历史记录结果失败: ' + error.message);
     }
 }
@@ -3173,7 +3185,7 @@ let allQueryLogs = []; // 存储所有日志
 
 async function refreshQueryLogs() {
     try {
-        const response = await fetch('/api/query-logs?grouped=true');
+        const response = await fetch('/api/query-logs?grouped=true&from_db=true');
         const result = await response.json();
         
         if (result.success && result.data) {
@@ -3366,19 +3378,19 @@ function filterLogsByLevel() {
 }
 
 async function clearQueryLogs() {
-    if (!confirm('确定要清空所有查询日志吗？')) {
+    if (!confirm('确定要清空所有查询日志吗？这将删除内存和数据库中的所有日志记录。')) {
         return;
     }
     
     try {
-        const response = await fetch('/api/query-logs', {
+        const response = await fetch('/api/query-logs?clear_db=true', {
             method: 'DELETE'
         });
         const result = await response.json();
         
         if (result.success) {
             document.getElementById('query-logs').innerHTML = '<div class="alert alert-info">查询日志已清空</div>';
-            showAlert('success', '查询日志已清空');
+            showAlert('success', result.message);
         } else {
             showAlert('danger', '清空查询日志失败: ' + result.error);
         }
@@ -3388,6 +3400,47 @@ async function clearQueryLogs() {
     }
 }
 
+// 清理旧日志
+async function cleanupOldLogs() {
+    const days = prompt('请输入要保留的天数（默认30天）:', '30');
+    if (days === null) return; // 用户取消
+    
+    const daysToKeep = parseInt(days) || 30;
+    if (daysToKeep <= 0) {
+        showAlert('warning', '保留天数必须大于0');
+        return;
+    }
+    
+    if (!confirm(`确定要清理超过 ${daysToKeep} 天的旧日志吗？`)) {
+        return;
+    }
+    
+    try {
+        const response = await fetch('/api/query-logs/cleanup', {
+            method: 'POST',
+            headers: {
+                'Content-Type': 'application/json'
+            },
+            body: JSON.stringify({
+                days_to_keep: daysToKeep
+            })
+        });
+        
+        const result = await response.json();
+        
+        if (result.success) {
+            showAlert('success', result.message);
+            // 刷新日志显示
+            refreshQueryLogs();
+        } else {
+            showAlert('danger', '清理旧日志失败: ' + result.error);
+        }
+    } catch (error) {
+        console.error('清理旧日志失败:', error);
+        showAlert('danger', '清理旧日志失败');
+    }
+}
+
 // 在查询执行后自动刷新日志
 function autoRefreshLogsAfterQuery() {
     // 延迟一下确保后端日志已经记录
diff --git a/templates/db_compare.html b/templates/db_compare.html
index fe6fa33..58b0cb1 100644
--- a/templates/db_compare.html
+++ b/templates/db_compare.html
@@ -707,6 +707,9 @@
                                             <button class="btn btn-sm btn-outline-primary me-2" onclick="refreshQueryLogs()">
                                                 <i class="fas fa-sync-alt"></i> 刷新
                                             </button>
+                                            <button class="btn btn-sm btn-outline-warning me-2" onclick="cleanupOldLogs()">
+                                                <i class="fas fa-broom"></i> 清理旧日志
+                                            </button>
                                             <button class="btn btn-sm btn-outline-danger" onclick="clearQueryLogs()">
                                                 <i class="fas fa-trash"></i> 清空
                                             </button>