I have this

I’m a new learner here. I’m having trouble to direct my page to my main page after form is being submitted. I will include my code here,

I have a code that builds a query according to parameters it receives from other pages. But sometimes, it can receive two of the same column name and it will write out something like this:

There is an error in the update code in Php Crud.

Accuracy is not maintained when tracking time.

i have two table in sql database 1st is booking and it has customers details and another is booking_line it has purchased products history by customers now i want both results in a array like following image
i just want an array named Customer has all purchased details customers wise

I tried to make an easy login in my university task, but faced on with some troubles.
When I press the button all works fine including request, but redirect doesn’t work at all, I tried to use js instead, but even then it works so bad, one time works, and another doesn’t an don’t really understand why I didn’t find the solution.

Fatal error: Uncaught Error: Class “mysqli” not found in C:businessindex.php:8 Stack trace: #0 {main} thrown in C:businessindex.php on line 8

I don’t see any problem with my code and yet I still get this error in my code which doesn’t make sense at all.