On DB Query PHP return NULL but are records [duplicate]

Question

[PHP 8.1/SQL 10.4]

DB Structure

CREATE TABLE `trundschreiben` (
  `rsID` int(11) NOT NULL,
  `rsMTGLemail` varchar(255) COLLATE latin1_german1_ci NOT NULL,
  `rsVersendet` tinyint(1) DEFAULT NULL,
  `rsVersanddatum` date DEFAULT NULL,
  `rsAbsender` varchar(255) COLLATE latin1_german1_ci DEFAULT NULL,
  `rssprache` varchar(3) COLLATE latin1_german1_ci NOT NULL,
  `rskurse` text COLLATE latin1_german1_ci NOT NULL,
  `rskurseplain` text COLLATE latin1_german1_ci NOT NULL,
  `rsfirmenname` varchar(255) COLLATE latin1_german1_ci DEFAULT NULL,
  `rstyp` int(10) UNSIGNED NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1 COLLATE=latin1_german1_ci;

PHP Code:

   $sql = "SELECT MAX(rsID) as rsid FROM trundschreiben";   
   $result = mysqli_query($db_link, $sql);  
   $nrRS =  mysqli_fetch_array($result, MYSQLI_ASSOC)

GOAL

Get the highest value of 'rsID' from the table

WHAT I TRIED

In phpmyadmin it works perfectly, the value is returned

QUESTION

In PHP, var_dump($nrRS); returns me a value of

array(1) { ["rsid"]=> NULL }

while the $result returns me this array

current_field: 0 
field_count: 1 
lengths: null 
num_rows: 1 
type:0

How come I can't receive the value as I expect? Thank you!

PHP returns me a value of null...where? You haven't shown any attempt to use the contents of $nrRS to output anything. What does var_dump($nrRS); return? — ADyson
– ADyson, Commented Aug 31, 2022 at 11:40
I think that could only happen if the table contains no rows - demo: dbfiddle.uk/… . If phpMyAdmin gives you results for the same query, then my guess would be that your PHP code is looking at a different copy of your database. — ADyson
– ADyson, Commented Aug 31, 2022 at 11:47

Your Common Sense · Accepted Answer · 2022-09-04 11:48:18Z

0

When your table is empty, the max value is NULL. After inserting at least one row in the table, your code will start returning a number.

PHP online environment

edited Sep 4, 2022 at 11:48

Your Common Sense

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answered Sep 4, 2022 at 11:43

Slava Rozhnev

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