fix(db): 修复事务中SQL错误时的回滚机制

- 添加txFailed标志跟踪事务内的SQL错误状态
- 在事务模式下遇到SQL错误时立即标记事务失败并阻止重试
- 修改Action方法确保SQL出错时强制回滚事务
- 为事务失败场景添加完整的单元测试覆盖
- 防止在事务已回滚的情况下继续执行后续操作导致数据不一致

db/query.go

@@ -62,15 +62,21 @@ func (that *HoTimeDB) queryWithRetry(query string, retried bool, args ...interfa
 	processedArgs := that.processArgs(args)
 
 	if that.testTx != nil {
-		if that.testMu != nil { that.testMu.Lock() }
+		if that.testMu != nil {
+			that.testMu.Lock()
+		}
 		resl, err = that.testTx.Query(query, processedArgs...)
 		that.LastErr.SetError(err)
 		if err != nil {
-			if that.testMu != nil { that.testMu.Unlock() }
+			if that.testMu != nil {
+				that.testMu.Unlock()
+			}
 			return nil
 		}
 		result := that.Row(resl)
-		if that.testMu != nil { that.testMu.Unlock() }
+		if that.testMu != nil {
+			that.testMu.Unlock()
+		}
 		return result
 	} else if that.Tx != nil {
 		resl, err = that.Tx.Query(query, processedArgs...)
@@ -80,7 +86,12 @@ func (that *HoTimeDB) queryWithRetry(query string, retried bool, args ...interfa
 
 	that.LastErr.SetError(err)
 	if err != nil {
-		if !retried {
+		if that.Tx != nil {
+			if that.txFailed != nil {
+				*that.txFailed = true
+			}
+		}
+		if !retried && that.Tx == nil {
 			if pingErr := db.Ping(); pingErr == nil {
 				return that.queryWithRetry(query, true, args...)
 			}
@@ -128,9 +139,13 @@ func (that *HoTimeDB) execWithRetry(query string, retried bool, args ...interfac
 	processedArgs := that.processArgs(args)
 
 	if that.testTx != nil {
-		if that.testMu != nil { that.testMu.Lock() }
+		if that.testMu != nil {
+			that.testMu.Lock()
+		}
 		resl, e = that.testTx.Exec(query, processedArgs...)
-		if that.testMu != nil { that.testMu.Unlock() }
+		if that.testMu != nil {
+			that.testMu.Unlock()
+		}
 	} else if that.Tx != nil {
 		resl, e = that.Tx.Exec(query, processedArgs...)
 	} else {
@@ -143,6 +158,14 @@ func (that *HoTimeDB) execWithRetry(query string, retried bool, args ...interfac
 		if that.testTx != nil {
 			return resl, that.LastErr
 		}
+		// 事务内不做连接级重试：死锁等错误会导致 MySQL 自动回滚事务，
+		// 在已回滚的 Tx 上重试会以 auto-commit 模式执行，造成数据不一致
+		if that.Tx != nil {
+			if that.txFailed != nil {
+				*that.txFailed = true
+			}
+			return resl, that.LastErr
+		}
 		if !retried {
 			if pingErr := that.DB.Ping(); pingErr == nil {
 				return that.execWithRetry(query, true, args...)