PHP的MySQL查询问题

Question

I want take tanggal and waktu fields with condition of it's max id and lumen_satu < 1000 .

Here's my code

<?php 
require_once 'koneksi.php';
$sql = "SELECT tanggal, waktu from nilai_lumen WHERE lumen_satu < 1000 AND id=(SELECT MAX(id) from nilai_lumen)";
$r = mysqli_query($conn,$sql);

$data = mysqli_fetch_row($r);
echo "$data[0] $data[1]"

When I ran it, I got nothing; because the last database insert is lumen_satu > 1000

I want to get id before that but because I use MAX(id) I get the last id inserted in database.

How can i fix this?

Answer 1

根据您的病情，我想这就是您想要的

$sql = "SELECT tanggal, waktu from nilai_lumen WHERE id=(SELECT MAX(id) from nilai_lumen WHERE lumen_satu < 1000)";

Answer 2

If you want to pick the row with max id where lumen_satu < 1000 and id column is set to auto increment then you can simply use order by and limit

SELECT tanggal, waktu 
FROM nilai_lumen 
WHERE lumen_satu < 1000
ORDER BY id DESC
LIMIT 1