display two second last value from database - php

Question

Good Morning....
I am using php MySQL to store the students marks in database....
my database table is like this...
25 63 96 85 65
56 56 96 36 23
56 78 98 45 12
Now I am trying to display last two values from database table and wants to show anywhere else on my website...
I am using below code...
<?php
$q = "SELECT CONCAT (a) FROM record ORDER BY id DESC
LIMIT 1;";
$result = mysql_query($q);
$data = mysql_fetch_array($result);
echo $data[0];
?>
The above code display only last value....which is 12 above shown table...
I want to display both 45 and 12 from above shown table like this...
{45}==>{12}
Can anybody correct my code....
Thanks...

Answer 1

As Saitama pointed out in the comments, the mysql_* functions are deprecated. Best to use PDO or the mysqli_* functions as they will be supported in the future.
I mention it at the start because it's hugely important for both security and ongoing support.
That being said, you need to do two things in order to get your desired result. First, your query must return more than 1 value, so the LIMIT must be increased as sgeddes pointed out, and then you must display both values, not just the first value in the list of returned values (which is what $data[0] is doing now - just returning the first item in the array).
Try something like this:
<?php
$q = "SELECT CONCAT (a) FROM record ORDER BY id DESC
LIMIT 2;";
$result = mysql_query($q);
$data = mysql_fetch_array($result);
echo "{" . $data[1] . "}==>{" . $data[0] . "}"; //prints: "{45}==>{12}"
?>
Essentially, since $data is an array, you need to convert it into a string. I did this above by referencing its elements, but that is a fairly crude way to do it. If for example there is only 1 value in the database, trying to echo $data[1] would throw a notice because there is no second value in the array.
implode is a handy method to use because you can convert an array into a string and use a value, like a comma, to glue the values together.
echo implode(", ", $data); //prints "12, 45" (12 first because it is the first item in the array)
If you're not sure a key exists in an array, you can use the empty function, which checks if the key is set (isset), and if it has a non-falsey value.
if (empty($data[0] == false) {
echo $data[0];
}
if (empty($data[1] == false) {
echo $data[1];
}
Documentation:
PDO documentation: http://php.net/manual/en/book.pdo.php
mysqli_* documentation: http://php.net/manual/en/book.mysqli.php
implode documentation: http://php.net/manual/en/function.implode.php
isset documentation:http://php.net/manual/en/function.isset.php
empty documentation:http://php.net/manual/en/function.empty.php

Answer 2

$query="SELECT CONCAT (a) FROM record ORDER BY id DESC
LIMIT 2";
Order by DESC Limit 2 get Last two records from Database.