RWACha-API/application/common/model/TeamLevelModel.php

<?php

namespace app\common\model;

use think\Model;

class TeamLevelModel extends Model
{

    protected $name = 'team_level';

    public function getTeamLevelName($level_id){
        if(!($level_id > 0)){
            return null;
        }
        $info = $this->where('level_id', $level_id)->find();
        if (is_null($info)) {
            return null;
        } else {
            return $info['name'];
        }
    }
}