出现索引问题时，查询/准备语句中未使用索引

Question

I am trying to perform a query and am getting the following error..

7Error: No index used in query/prepared statement SELECT `id`, `category_id`, `topic_id`, `post_creator`, `post_content`, `post_date` FROM forum_posts WHERE `category_id`=? AND `topic_id`=?

I originally had this line of code for it...

if($stmt2 = $con->prepare("SELECT * FROM forum_posts WHERE `category_id`=? AND `topic_id`=?")) {

So I tried changing it to the following to give it an index.

if($stmt2 = $con->prepare("SELECT `id`, `category_id`, `topic_id`, `post_creator`, `post_content`, `post_date` FROM forum_posts WHERE `category_id`=? AND `topic_id`=?")) {

Why would this error be occuring? I have php error reporting on.

error_reporting(E_ALL);
ini_set('display_errors', 1);

However, even when I comment it out, the error still occurs and it kills my code. Anyone know why this error is coming up and how I can fix it?

Answer 1

According to the answer provided here :

mysqli_report(MYSQLI_REPORT_ALL ^ MYSQLI_REPORT_INDEX);

Turns off "Report if no index or bad index was used in a query" yet keeps other reporting on.

By using 'E_ALL', you are enabling the reporting of this error/warning.