CODE

import wixData from 'wix-data';

$w.onReady(function () {   });

export function BTN_click(event) { start_Function()  }

function  start_Function() {

    wixData.query("Books").include("author").find()

    .then( (results) => {

        if(results.items.length > 0) {

        let books = results.items;

        let firstBook = books[0];

        let firstAuthor = firstBook.author;

        console.log(books)

        console.log(firstBook)

        let output1 = [], output2 = []

        for (var i = 1; i < results.items.length; i++) {

            output1.push(books[i].author.authorFirstname)

            output2.push(books[i].author.authorLastname)

        }

        console.log(output1, output2)

        $w('#TXToutput1').text=output1.toString()

        $w('#TXToutput2').text=output2.toString()

    } else {    }

  } )

}