fix the Postgres database transaction cannot continue to execute after failure (#50)

pkg/datastore/database.go

@@ -4,11 +4,13 @@ import (
 	"xorm.io/xorm"
 
 	"github.com/mayswind/ezbookkeeping/pkg/core"
+	"github.com/mayswind/ezbookkeeping/pkg/settings"
 )
 
 // Database represents a database instance
 type Database struct {
-	engineGroup *xorm.EngineGroup
+	databaseType string
+	engineGroup  *xorm.EngineGroup
 }
 
 // NewSession starts a new session with the specified context
@@ -41,3 +43,23 @@ func (db *Database) DoTransaction(c core.Context, fn func(sess *xorm.Session) er
 
 	return nil
 }
+
+// SetSavePoint sets a save point in the current transaction for Postgres
+func (db *Database) SetSavePoint(sess *xorm.Session, savePointName string) error {
+	if db.databaseType == settings.PostgresDbType {
+		_, err := sess.Exec("SAVEPOINT " + savePointName)
+		return err
+	}
+
+	return nil
+}
+
+// RollbackToSavePoint rolls back to the specified save point in the current transaction for Postgres
+func (db *Database) RollbackToSavePoint(sess *xorm.Session, savePointName string) error {
+	if db.databaseType == settings.PostgresDbType {
+		_, err := sess.Exec("ROLLBACK TO SAVEPOINT " + savePointName)
+		return err
+	}
+
+	return nil
+}