fix(db): 修复事务模式下的错误处理与回滚机制

- 在 `queryWithRetry` 和 `execWithRetry` 方法中添加对 `txFailed` 的状态管理，确保在 SQL 错误时正确标记事务失败
- 增加新的测试用例以验证事务模式下的错误处理逻辑，确保在 SQL 错误发生时能够正确回滚
- 优化测试数据库的初始化方法，支持事务测试场景

db/transaction_test.go

@@ -3,6 +3,7 @@ package db
 import (
 	. "code.hoteas.com/golang/hotime/common"
 	"database/sql"
+	"sync"
 	"testing"
 
 	"github.com/sirupsen/logrus"
@@ -34,6 +35,18 @@ func newTestDB(t *testing.T) *HoTimeDB {
 	return db
 }
 
+func newTestDBWithTestTx(t *testing.T) *HoTimeDB {
+	t.Helper()
+	db := newTestDB(t)
+	tx, err := db.DB.Begin()
+	if err != nil {
+		t.Fatal(err)
+	}
+	db.testTx = tx
+	db.testMu = &sync.Mutex{}
+	return db
+}
+
 func TestAction_TxFailedForceRollback(t *testing.T) {
 	db := newTestDB(t)
 	defer db.DB.Close()
@@ -133,3 +146,105 @@ func TestAction_SqlErrorThenReturnTrue_MustRollback(t *testing.T) {
 		t.Fatalf("value should be rolled back to 100 (original), got %d", val)
 	}
 }
+
+// --- testTx (SAVEPOINT) 模式测试 ---
+
+func TestAction_TestTx_SqlErrorForceRollbackSavepoint(t *testing.T) {
+	db := newTestDBWithTestTx(t)
+	defer db.testTx.Rollback()
+	defer db.DB.Close()
+
+	db.testTx.Exec("UPDATE test_item SET value = 100 WHERE id = 1")
+
+	result := db.Action(func(tx HoTimeDB) (isSuccess bool) {
+		tx.Update("test_item", Map{"value": 888}, Map{"id": 1})
+
+		tx.Exec("THIS IS INVALID SQL")
+
+		return true
+	})
+
+	if result != false {
+		t.Fatalf("Action (testTx mode) should return false when SQL error occurred, got true")
+	}
+
+	db.testMu.Lock()
+	rows, err := db.testTx.Query("SELECT value FROM test_item WHERE id = 1")
+	db.testMu.Unlock()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer rows.Close()
+	if !rows.Next() {
+		t.Fatal("no row found")
+	}
+	var val int64
+	rows.Scan(&val)
+	if val != 100 {
+		t.Fatalf("value should be rolled back to 100 via SAVEPOINT, got %d", val)
+	}
+}
+
+func TestAction_TestTx_NormalCommitSavepoint(t *testing.T) {
+	db := newTestDBWithTestTx(t)
+	defer db.testTx.Rollback()
+	defer db.DB.Close()
+
+	result := db.Action(func(tx HoTimeDB) (isSuccess bool) {
+		tx.Update("test_item", Map{"value": 777}, Map{"id": 1})
+		return true
+	})
+
+	if result != true {
+		t.Fatalf("Action (testTx mode) should return true on success, got false")
+	}
+
+	db.testMu.Lock()
+	rows, err := db.testTx.Query("SELECT value FROM test_item WHERE id = 1")
+	db.testMu.Unlock()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer rows.Close()
+	if !rows.Next() {
+		t.Fatal("no row found")
+	}
+	var val int64
+	rows.Scan(&val)
+	if val != 777 {
+		t.Fatalf("value should be 777 after RELEASE SAVEPOINT, got %d", val)
+	}
+}
+
+func TestAction_TestTx_NormalRollbackSavepoint(t *testing.T) {
+	db := newTestDBWithTestTx(t)
+	defer db.testTx.Rollback()
+	defer db.DB.Close()
+
+	db.testTx.Exec("UPDATE test_item SET value = 100 WHERE id = 1")
+
+	result := db.Action(func(tx HoTimeDB) (isSuccess bool) {
+		tx.Update("test_item", Map{"value": 666}, Map{"id": 1})
+		return false
+	})
+
+	if result != false {
+		t.Fatalf("Action (testTx mode) should return false, got true")
+	}
+
+	db.testMu.Lock()
+	rows, err := db.testTx.Query("SELECT value FROM test_item WHERE id = 1")
+	db.testMu.Unlock()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer rows.Close()
+	if !rows.Next() {
+		t.Fatal("no row found")
+	}
+	var val int64
+	rows.Scan(&val)
+	if val != 100 {
+		t.Fatalf("value should be rolled back to 100 via SAVEPOINT, got %d", val)
+	}
+}