cannot use ctx in promise'then
```
  static  like(ctx){
    const {unionId,topicId} = ctx.request.body
    console.log(unionId);
    LikeModel.findOrCreate({
      where:{topicId},
      defaults:{
        unionId,topicId
      }
      // attributes: { exclude: ['id'] } 
    }).spread(async (data,created)=>{
      if(created){
        ctx.body={mes:'success'}
      }else{
        console.log(23232)
        await LikeModel.destroy({
          where:{topicId}
        }).then((res)=>{
          console.log(res)  //above here is ok
          ctx.status = 200
          ctx.body = {mes:'fail'}
        })
      }
    })
  }
```

just the last code  do not works
``
 ctx.status = 200
ctx.body = {mes:'fail'}
```

why??