server site:
app.post('/myaction', async function(req, res) {
async function next_func(req, res){
   var myJson =  await show();
   return myJson;
}
dataJ =  await next_func(req, res);
console.log("dataJ="+dataJ);
console.log(typeof dataJ)
res.status(200);
res.contentType('application/json');
res.send(dataJ);
});
app.listen(8081, function() {
console.log('Server running at http://127.0.0.1:8081/');
});
async function show(){
 var con = mysql.createConnection({
 host: "127.0.0.1",
 user: "root",
 password: "aaaaaaaa",
 database: "doto"
 });
 var sql ="select * from task_list";
 resultsArray = [];
 await new Promise((resolve, reject) => {
 con.connect((err, connection) => {
    if (err) return reject(err)
    con.query(sql, (err, rows, fields) => {
         if (err) return reject(err)
         resolve(
             rows.forEach( (row) => {
            resultsArray.push(
    {detail:row.details, status:row.status, subject:row.subject}
   );
              })
         )
    })
 })
})
 console.log("resultsArray"+resultsArray);
 return  resultsArray;
}
client site:
$.fn.ajaxShow = function(st) {
xhrct =  $.ajax({
                    type: 'POST',,
                    data : {
                          status : st
                          },
                    url: 'http://127.0.0.1:8081/myaction',
                    success: function (data) {
                        alert("function");
                               $('#tb').empty();
                               if(data!=null) {
                                 var fotoData = $.parseJSON(data);
                                  $(fotoData).each(function (i, obx) {
                                        alert("fotoData");
                                        $('#tb').append('<tr>')

.append('<td>'+obx.detail+'</td>')

.append('<td>'+obx.status+'</td>')

.append('<td>'+obx.subject+'</td>')
.append('</tr>');
    });
  }
},
error: function(XMLHttpRequest, textStatus, errorThrown) {
    alert("XMLHttpRequest: "+XMLHttpRequest.responseText);
    alert("textStatus: "+textStatus);
    alert("errorThrown: "+errorThrown);
    }
  });
}