const router = require('koa-router')()
 
const prestoClient=require('presto-client');
router.get('/query', async function (ctx,next) {
      var queryData=function(){
          var client = new prestoClient.Client({
                host: '*.*.*.*',
                port:8889,
                catalog: 'hive',
                schema: 'default',
           });
    
           return new Promise(function (resolve, reject) {
             client.execute({
                   query:   'select xm,xh,rxrq from t_bzks limit 5',
                   data:    function(error, data, columns, stats){
                         console.log(data);
                         resolve([columns,data]);
                        },
                   success: function(error, stats){ },
                   error:   function(error){}
             });

           });

    };
      
     var data=await queryData();
     ctx.body = {
        cols:data[0].map(function(item){return item.name;}),//只要列名
        ary: data[1]
     }

});

module.exports = router