strtotime from while variable show wrong result-CodePudding

i want to query less than 1 month from below data

$mysqli = new mysqli($server, $username, $password, $database);

// cek koneksi
if ($mysqli->connect_error) {
    die('Koneksi Database Gagal : '.$mysqli->connect_error);
}
$query = mysqli_query($mysqli, "SELECT tgl_exp FROM i_test ")
 or die('Ada kesalahan pada query tampil Data Barang: '.mysqli_error($mysqli));

 while ($data = mysqli_fetch_assoc($query))
{
    echo "$data[tgl_exp]<br>";                                          
}

$newdate = date('Y-m-d',strtotime('-1 month',strtotime($data)));
echo $newdate;

but why the result is wrong like picture below?

please give me the clue, thank you for the help

CodePudding user response：

You need to call strtotime() inside the loop, when $data contains a valid row. After the loop is done, $data is empty.

And the argument has to be $data['tgl_exp']. $data is the whole row, which is an array.

$mysqli = new mysqli($server, $username, $password, $database);

// cek koneksi
if ($mysqli->connect_error) {
    die('Koneksi Database Gagal : '.$mysqli->connect_error);
}
$query = mysqli_query($mysqli, "SELECT tgl_exp FROM i_test ")
 or die('Ada kesalahan pada query tampil Data Barang: '.mysqli_error($mysqli));

 while ($data = mysqli_fetch_assoc($query))
{
    echo "$data[tgl_exp]<br>";
    $newdate = date('Y-m-d',strtotime('-1 month',strtotime($data['tgl_exp'])));
    echo $newdate . '<br>';                         
}

$newdate = date('Y-m-d',strtotime('-1 month',strtotime($data)));
echo $newdate;