新增菜单，修改角色，分页

api/model/model.go

@@ -121,3 +121,21 @@ func (m *Model) BeforeCreate(tx *gorm.DB) (err error) {
 
 	return nil
 }
+
+func Paginate(page, pageSize int) func(db *gorm.DB) *gorm.DB {
+	return func(db *gorm.DB) *gorm.DB {
+		if page <= 0 {
+			page = 1
+		}
+
+		switch {
+		case pageSize > 100:
+			pageSize = 100
+		case pageSize <= 0:
+			pageSize = 10
+		}
+
+		offset := (page - 1) * pageSize
+		return db.Offset(offset).Limit(pageSize)
+	}
+}