21.04.26 게시판 번호 처리

app.get('/list', (req, res) => {
   	// order by desc 내림차순
    connection.query("SELECT idx, subject, board_name, content, 
    date_format(today,'%Y-%m-%d') as today, 
    hit FROM board order by idx desc", (error, results) => {
        if (error) {
            console.log(error);
        } else {
            let total_record = results.length;
            results.forEach(ele=>{
                console.log(ele);
                ele.number = total_record;
                total_record--;
            });

            res.render('list.html', {
                list: results,
            });
        }
    });
});

이 부분 - idx 대신 number란 변수를 쓰게되어 중간에 값을 삭제해도 비는 숫자 없이 정렬됨

                total_record 에 글의 전체 개수 (results.length)를 담는다.

                배열.forEach를 돌림 (ele는 배열 원소- 글 하나하나)

                ele에 number 라는 변수를 만들어준다. 여기에 total_record 즉, 글의 전체 개수를 담는다.

                forEach문이 돌면서 total_record=전체 글의 개수에서 하나씩 빼면서 그걸 number에 준다.