如何从MYSQL中获取单个值并将其保存到JavaScript变量？

Question

I want to select the last row of my table, and save all the values to separate JavaScript variables. I used the query in PHP:

$sql = "SELECT * from reading ORDER BY id DESC LIMIT 1";

to select the last row of the table. I don't know how to proceed.

Answer 1

PHP:

$sql = "SELECT * from reading ORDER BY id DESC LIMIT 1";
if ($query = mysqli_query($link, $sql)) {
     // fetch one result 
    $row = mysqli_fetch_row($query);
    echo json_encode($row);
}

jQuery:

// sample variables
var username = "";
var password = "";
var phpUrl = 'http://sampleurl.com/mypage.php';
$.getJSON(phpUrl, function (result) {
    $.each(result, function (data) {
        // if data sent back is eg data:[{username:'sample', password:'sample'}]
        // then you fetch and save as 
        username = data.username;
        password = data.password;
    });
});

Answer 2

cookies way is definitely the way to go. If you are doing all of this on one page and just need a quick fix you could do

<?php
$sql = "SELECT * from reading ORDER BY id DESC LIMIT 1";
if ($query = mysqli_query($link, $sql)) {
     // fetch one result 
    $row = mysqli_fetch_row($query);
    $json_string = json_encode($row);
}
?>

<script> var sql_row = <?php echo $json_string; ?>; </script>

This is the lazy way and will get messy quickly, but it could be useful for understanding how PHP and JS work together