Now the below behaviours are allowed.
```Go
var id int64
var name string
has, err := engine.Table(&user).Cols("id", "name").Get(&id, &name)
// SELECT id, name FROM user LIMIT 1
```
```Go
rows, err := engine.Cols("name", "age").Rows(&User{Name:name})
// SELECT * FROM user
defer rows.Close()
for rows.Next() {
var name string
var age int
err = rows.Scan(&name, &age)
}
```
Reviewed-on: https://gitea.com/xorm/xorm/pulls/2029
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-committed-by: Lunny Xiao <xiaolunwen@gmail.com>
Lunny Xiao