Yii：以最高平均评级为基础获取数据

I am a yiibie and I want to get the top 5 ngo's from my "NgoRateReviewNgo" table. The condition for the top 5 Ngo's is that it should first find the average rating of the Ngo's and after that those 5 Ngo's which have highest average rating gets displayed. This is the code for my view file and contains the SQL queryI am a yiibie and I want to get the top 5 ngo's