feat: Add MySQL database support (#3024)MySQL-databases

* feat: Add MySQL database support

- Add MySQL database support with environment-based configuration
- Fix MySQL compatibility issue with 'key' column name
- Maintain SQLite as default database
- Add proper validation for MySQL configuration
- Test and verify compatibility with existing database
- Replaced raw SQL queries using JSON_EACH functions with standard GORM queries
- Modified functions to handle JSON parsing in Go code instead of database since JSON_EACH is not available on MySQL or MariaDB:
  - getAllEmails()
  - GetClientTrafficByID()
  - getFallbackMaster()
  - MigrationRemoveOrphanedTraffics()

The system now supports both MySQL and SQLite databases, with SQLite remaining as the default option. MySQL connection is only used when explicitly configured through environment variables.

* refactor: prefix env variables of database with XUI_ to support direct environment usage without .env file

All database configuration environment variables now start with the XUI_ prefix to avoid conflicts and allow configuration via system-level environment variables, not just the .env file.

1 files changed, 2 insertions, 2 deletions

diff --git a/web/service/setting.go b/web/service/setting.go
index 62d66c11..8fe3ec01 100644
--- a/web/service/setting.go
+++ b/web/service/setting.go
@@ -88,7 +88,7 @@ func (s *SettingService) GetDefaultJsonConfig() (any, error) {
 func (s *SettingService) GetAllSetting() (*entity.AllSetting, error) {
 	db := database.GetDB()
 	settings := make([]*model.Setting, 0)
-	err := db.Model(model.Setting{}).Not("key = ?", "xrayTemplateConfig").Find(&settings).Error
+	err := db.Model(model.Setting{}).Not("`key` = ?", "xrayTemplateConfig").Find(&settings).Error
 	if err != nil {
 		return nil, err
 	}
@@ -173,7 +173,7 @@ func (s *SettingService) ResetSettings() error {
 func (s *SettingService) getSetting(key string) (*model.Setting, error) {
 	db := database.GetDB()
 	setting := &model.Setting{}
-	err := db.Model(model.Setting{}).Where("key = ?", key).First(setting).Error
+	err := db.Model(model.Setting{}).Where("`key` = ?", key).First(setting).Error
 	if err != nil {
 		return nil, err
 	}