diff --git a/server/cmd/main.go b/server/cmd/main.go
index 5517235..95abcbc 100644
--- a/server/cmd/main.go
+++ b/server/cmd/main.go
@@ -67,7 +67,6 @@ func main() {
 
 		// app management
 		admin.POST("/app/list", appHandler.List)
-		admin.GET("/app/tree", appHandler.Tree)
 		admin.GET("/app/:id", appHandler.GetById)
 		admin.POST("/app/add", appHandler.Add)
 		admin.POST("/app/update", appHandler.Update)
diff --git a/server/internal/config/config.go b/server/internal/config/config.go
index 81835fa..6eee5ab 100644
--- a/server/internal/config/config.go
+++ b/server/internal/config/config.go
@@ -137,5 +137,5 @@ func intProp(props map[string]string, key string, defaultVal int) int {
 }
 
 func (d *DatabaseConfig) DSN() string {
-	return d.User + ":" + d.Password + "@tcp(" + d.Host + ":" + strconv.Itoa(d.Port) + ")/" + d.Name + "?charset=utf8&parseTime=true"
+	return d.User + ":" + d.Password + "@tcp(" + d.Host + ":" + strconv.Itoa(d.Port) + ")/" + d.Name + "?charset=utf8&parseTime=true&loc=Local"
 }
diff --git a/server/internal/dao/engine.go b/server/internal/dao/engine.go
index fa3885e..aba7001 100644
--- a/server/internal/dao/engine.go
+++ b/server/internal/dao/engine.go
@@ -1,7 +1,6 @@
 package dao
 
 import (
-	"fmt"
 	"kenaito-conf/server/internal/config"
 	"kenaito-conf/server/internal/model"
 	"kenaito-conf/server/internal/util"
@@ -14,9 +13,7 @@ import (
 var Engine *xorm.Engine
 
 func Init() error {
-	cfg := config.Cfg.Database
-	dsn := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=utf8&parseTime=true&loc=Local",
-		cfg.User, cfg.Password, cfg.Host, cfg.Port, cfg.Name)
+	dsn := config.Cfg.Database.DSN()
 
 	var err error
 	Engine, err = xorm.NewEngine("mysql", dsn)
diff --git a/server/internal/handler/app.go b/server/internal/handler/app.go
index 48e45d7..1850e8e 100644
--- a/server/internal/handler/app.go
+++ b/server/internal/handler/app.go
@@ -48,7 +48,7 @@ func (h *AppHandler) List(c *gin.Context) {
 	total, _ := query.Count(&model.Application{})
 	query.Limit(req.PageSize, (req.PageNo-1)*req.PageSize).Find(&apps)
 
-	// load group names
+	// load group names - batch query to avoid N+1
 	groupIds := make(map[int]bool)
 	for _, app := range apps {
 		if app.GroupId != nil {
@@ -56,10 +56,15 @@ func (h *AppHandler) List(c *gin.Context) {
 		}
 	}
 	groupMap := make(map[int]string)
-	for gid := range groupIds {
-		var group model.BusinessGroup
-		if has, _ := dao.Engine.ID(gid).Get(&group); has {
-			groupMap[gid] = group.Name
+	if len(groupIds) > 0 {
+		ids := make([]int, 0, len(groupIds))
+		for gid := range groupIds {
+			ids = append(ids, gid)
+		}
+		var groups []model.BusinessGroup
+		dao.Engine.In("id", ids).Find(&groups)
+		for _, g := range groups {
+			groupMap[g.Id] = g.Name
 		}
 	}
 	for i := range apps {
@@ -82,38 +87,6 @@ func (h *AppHandler) GetById(c *gin.Context) {
 	c.JSON(http.StatusOK, model.WrapperResponse{Code: 0, Data: app})
 }
 
-func (h *AppHandler) Tree(c *gin.Context) {
-	var apps []model.Application
-	dao.Engine.Find(&apps)
-
-	tree := make(map[string]*AppTreeModel)
-	for _, app := range apps {
-		node := &AppTreeModel{
-			Id:        strconv.Itoa(app.Id),
-			Name:      app.Name,
-			Code:      app.Code,
-			ServiceId: app.ServiceId,
-			Children:  make([]*AppTreeModel, 0),
-		}
-		tree[strconv.Itoa(app.Id)] = node
-	}
-
-	result := make([]*AppTreeModel, 0)
-	for _, app := range apps {
-		node := tree[strconv.Itoa(app.Id)]
-		if app.ParentId == nil {
-			result = append(result, node)
-		} else {
-			parentId := strconv.Itoa(*app.ParentId)
-			if parent, ok := tree[parentId]; ok {
-				parent.Children = append(parent.Children, node)
-			}
-		}
-	}
-
-	c.JSON(http.StatusOK, model.WrapperResponse{Code: 0, Data: result})
-}
-
 type AddAppRequest struct {
 	Id        int    `json:"id"`
 	GroupId   *int   `json:"groupId"`
@@ -295,14 +268,6 @@ func (h *AppHandler) Options(c *gin.Context) {
 	c.JSON(http.StatusOK, model.WrapperResponse{Code: 0, Data: options})
 }
 
-type AppTreeModel struct {
-	Id        string          `json:"id"`
-	Name      string          `json:"name"`
-	Code      string          `json:"code"`
-	ServiceId string          `json:"serviceId,omitempty"`
-	Children  []*AppTreeModel `json:"children"`
-}
-
 func (h *AppHandler) GenerateToken(c *gin.Context) {
 	id, _ := strconv.Atoi(c.Param("id"))
 	userInfo := middleware.GetUserInfo(c)
diff --git a/server/internal/handler/config.go b/server/internal/handler/config.go
index e0f0a72..9bf9828 100644
--- a/server/internal/handler/config.go
+++ b/server/internal/handler/config.go
@@ -45,10 +45,7 @@ func (h *ConfigHandler) List(c *gin.Context) {
 		if *req.AppId <= 0 {
 			query = query.And("(app_id is null OR app_id = 0)")
 		} else {
-			var app model.Application
-			if has, _ := dao.Engine.ID(*req.AppId).Get(&app); has {
-				query = query.And("app_code like ?", app.Code+"%")
-			}
+			query = query.And("app_id = ?", *req.AppId)
 		}
 	}
 
diff --git a/server/internal/handler/profile.go b/server/internal/handler/profile.go
index 3144642..ee56fa1 100644
--- a/server/internal/handler/profile.go
+++ b/server/internal/handler/profile.go
@@ -6,6 +6,7 @@ import (
 	"kenaito-conf/server/internal/model"
 	"net/http"
 	"strconv"
+	"time"
 
 	"github.com/gin-gonic/gin"
 )
@@ -64,6 +65,7 @@ func (h *ProfileHandler) Add(c *gin.Context) {
 		Alias:     req.Alias,
 		IsDefault: req.IsDefault,
 		Enabled:   true,
+		CreatedAt: func() *time.Time { t := time.Now(); return &t }(),
 	}
 
 	dao.Engine.Insert(&profile)
@@ -104,7 +106,9 @@ func (h *ProfileHandler) Update(c *gin.Context) {
 	}
 
 	profile.Alias = req.Alias
-	dao.Engine.ID(profile.Id).Update(&profile)
+	now := time.Now()
+	profile.UpdatedAt = &now
+	dao.Engine.ID(profile.Id).Cols("alias", "is_default", "updated_at").Update(&profile)
 
 	c.JSON(http.StatusOK, model.WrapperResponse{Code: 0, Data: true})
 }
diff --git a/server/internal/handler/user.go b/server/internal/handler/user.go
index 6d1f5db..2d109cd 100644
--- a/server/internal/handler/user.go
+++ b/server/internal/handler/user.go
@@ -27,7 +27,7 @@ func (h *UserHandler) List(c *gin.Context) {
 	userInfo := middleware.GetUserInfo(c)
 
 	var users []model.User
-	query := dao.Engine.Where("1=1")
+	query := dao.Engine.Where("enabled = 1")
 
 	if !userInfo.IsSuperAdmin() && userInfo.GroupId != nil {
 		query = query.And("group_id = ?", *userInfo.GroupId)
@@ -84,13 +84,13 @@ func (h *UserHandler) Add(c *gin.Context) {
 		return
 	}
 
-	// check name exists
+	// check name exists - only check active users (enabled = 1)
 	var existing model.User
-	if has, _ := dao.Engine.Where("name = ?", req.Name).Get(&existing); has {
+	if has, _ := dao.Engine.Where("name = ? AND enabled = 1", req.Name).Get(&existing); has {
 		c.JSON(http.StatusOK, model.WrapperResponse{Code: 1001, Msg: "用户名已存在"})
 		return
 	}
-	if has, _ := dao.Engine.Where("mobile = ?", req.Mobile).Get(&existing); has {
+	if has, _ := dao.Engine.Where("mobile = ? AND enabled = 1", req.Mobile).Get(&existing); has {
 		c.JSON(http.StatusOK, model.WrapperResponse{Code: 1001, Msg: "手机号已存在"})
 		return
 	}
@@ -150,7 +150,7 @@ func (h *UserHandler) Update(c *gin.Context) {
 	userId, _ := strconv.Atoi(userInfo.Id)
 
 	var user model.User
-	has, _ := dao.Engine.ID(userId).Get(&user)
+	has, _ := dao.Engine.Where("id = ? AND enabled = 1", userId).Get(&user)
 	if !has {
 		c.JSON(http.StatusOK, model.WrapperResponse{Code: 404, Msg: "用户不存在"})
 		return
@@ -203,7 +203,7 @@ func (h *UserHandler) AdminUpdate(c *gin.Context) {
 	}
 
 	var user model.User
-	has, _ := dao.Engine.ID(req.Id).Get(&user)
+	has, _ := dao.Engine.Where("id = ? AND enabled = 1", req.Id).Get(&user)
 	if !has {
 		c.JSON(http.StatusOK, model.WrapperResponse{Code: 404, Msg: "用户不存在"})
 		return
@@ -264,7 +264,7 @@ func (h *UserHandler) Delete(c *gin.Context) {
 	userInfo := middleware.GetUserInfo(c)
 
 	var user model.User
-	has, _ := dao.Engine.ID(id).Get(&user)
+	has, _ := dao.Engine.Where("id = ? AND enabled = 1", id).Get(&user)
 	if !has {
 		c.JSON(http.StatusOK, model.WrapperResponse{Code: 404, Msg: "用户不存在"})
 		return
@@ -275,7 +275,10 @@ func (h *UserHandler) Delete(c *gin.Context) {
 		return
 	}
 
-	dao.Engine.ID(id).Delete(&model.User{})
+	user.Enabled = false
+	now := time.Now()
+	user.UpdatedAt = &now
+	dao.Engine.ID(user.Id).Cols("enabled", "updated_at").Update(&user)
 
 	c.JSON(http.StatusOK, model.WrapperResponse{Code: 0})
 }
@@ -283,7 +286,7 @@ func (h *UserHandler) Delete(c *gin.Context) {
 func (h *UserHandler) ResetPassword(c *gin.Context) {
 	id, _ := strconv.Atoi(c.Param("id"))
 	var user model.User
-	has, _ := dao.Engine.ID(id).Get(&user)
+	has, _ := dao.Engine.Where("id = ? AND enabled = 1", id).Get(&user)
 	if !has {
 		c.JSON(http.StatusOK, model.WrapperResponse{Code: 404, Msg: "用户不存在"})
 		return
@@ -302,7 +305,7 @@ func (h *UserHandler) ResetPassword(c *gin.Context) {
 func (h *UserHandler) Switch(c *gin.Context) {
 	id, _ := strconv.Atoi(c.Param("id"))
 	var user model.User
-	has, _ := dao.Engine.ID(id).Get(&user)
+	has, _ := dao.Engine.Where("id = ? AND enabled = 1", id).Get(&user)
 	if !has {
 		c.JSON(http.StatusOK, model.WrapperResponse{Code: 404, Msg: "用户不存在"})
 		return
diff --git a/server/internal/model/profile.go b/server/internal/model/profile.go
index 1006004..7788e8a 100644
--- a/server/internal/model/profile.go
+++ b/server/internal/model/profile.go
@@ -1,11 +1,15 @@
 package model
 
+import "time"
+
 type Profile struct {
-	Id        int    `xorm:"int autoincr pk" json:"id"`
-	Name      string `xorm:"varchar(32)" json:"name"`
-	Alias     string `xorm:"varchar(32)" json:"alias"`
-	IsDefault bool   `xorm:"tinyint(1) default 0" json:"isDefault"`
-	Enabled   bool   `xorm:"tinyint(1) default 1" json:"enabled"`
+	Id        int        `xorm:"int autoincr pk" json:"id"`
+	Name      string     `xorm:"varchar(32)" json:"name"`
+	Alias     string     `xorm:"varchar(32)" json:"alias"`
+	IsDefault bool       `xorm:"tinyint(1) default 0" json:"isDefault"`
+	Enabled   bool       `xorm:"tinyint(1) default 1" json:"enabled"`
+	CreatedAt *time.Time `xorm:"datetime" json:"createdAt"`
+	UpdatedAt *time.Time `xorm:"datetime" json:"updatedAt"`
 }
 
 type AppExtrAttr struct {
diff --git a/web/src/api/app.js b/web/src/api/app.js
index 2af89a6..04c7323 100644
--- a/web/src/api/app.js
+++ b/web/src/api/app.js
@@ -8,13 +8,6 @@ export function getAppList(params) {
   })
 }
 
-export function getAppTree() {
-  return request({
-    url: '/admin/app/tree',
-    method: 'get'
-  })
-}
-
 export function getApp(id) {
   return request({
     url: `/admin/app/${id}`,