gorm对多个字段排序:

// 多字段排序,一个Order
common.Db.Order("age desc, name").Find(&users)
// SELECT * FROM users ORDER BY age desc, name;

// 多字段排序,多个order
common.Db.Order("age desc").Order("name").Find(&users)
// SELECT * FROM users ORDER BY age desc, name;

// 覆盖排序
common.Db.Order("age desc").Find(&users1).Order("age", true).Find(&users2)
// SELECT * FROM users ORDER BY age desc; (users1)
// SELECT * FROM users ORDER BY age; (users2)

//对Order进行封装
//TODO