Prepared statement fails when i changed database - php

Question

the issue
So I bumped into something curious this morning when I was updating my database. I executed a collation change in my database, changing it from latin1 to uft8. However, my queries failed suddenly on my table. After some debugging, (rebuilding the table even with its original setup, but to no such avail) and receiving 500 internal errors, i realized it had to do with the prepared statement, so i tore it out, and replaced it with a regular mysqli_query, and it surprisingly worked. So now I am wondering, was my prepared statement wrong the whole time, or did it fail because of a change in the database.
the setup
This is the current table set up. I changed it back to latin (and its innoDB) yet it didnt gave me the results back i wanted when i changed everything back to the original settings (which is how it is now)
the code
the original code was this and it worked fine until the change
require_once '../db/dbControl.php';
$id = mysqli_real_escape_string($con,$_GET["id"]);
$sql = "SELECT *
FROM project
WHERE project.ProjectId = ? ";
$stmt1 = mysqli_prepare($con, $sql);
mysqli_stmt_bind_param($stmt1,'i',$id);
mysqli_stmt_execute($stmt1);
mysqli_stmt_bind_result($stmt1,$ProjectId,$ProjectTitel,$ProjectOmschrijving, $ProjectOmschrijving,$ProjectDatum,$ProjectClient,$ProjectUrl);
while (mysqli_stmt_fetch($stmt1)){
the code itself of the page
}
So right now I am just using a regular mysqli_query in order to make it work
require_once '../db/dbControl.php';
id = mysqli_real_escape_string($con,$_GET["id"]);
$sql = "SELECT *
FROM project
WHERE project.ProjectId = '". $id ."'";
$result = mysqli_query($con,$sql);
while($rows=mysqli_fetch_array($result)){
$ProjectId = $rows['ProjectId'];
$ProjectTitel = $rows['ProjectTitel'];
$ProjectExpertise = $rows['ProjectExpertise'];
$ProjectOmschrijving = $rows['ProjectOmschrijving'];
$ProjectDatum = $rows['ProjectDatum'];
$ProjectClient = $rows['ProjectClient'];
$ProjectUrl = $rows['ProjectUrl'];
the code itself of the page
}
I am a little bit confused (maybe i overlooked something here because to focussed on a little bit of code) but it only happens on the project table. I checked it against code that involves readouts, and they work all fine with prepped statements.
Hope anyone can spot what I couldn't

Answer 1

I wont be able to tell you what happened but here are two thought's.
The prepared statement execution consists of two stages: prepare and
execute. At the prepare stage a statement template is sent to the
database server. The server performs a syntax check and initializes
server internal resources for later use.
A prepared statement can be executed repeatedly. Upon every execution
the current value of the bound variable is evaluated and sent to the
server. The statement is not parsed again. The statement template is
not transferred to the server again.
Maybe this is what happened, it could be that the prepared statements never reseted after you changed to utf8.
Every prepared statement occupies server resources. Statements should be closed explicitly immediately after use. If not done explicitly, the statement will be closed when the statement handle is freed by PHP.
Using a prepared statement is not always the most efficient way of
executing a statement. A prepared statement executed only once causes
more client-server round-trips than a non-prepared statement. This is
why the SELECT is not run as a prepared statement above.
Maybe the server memory (is/was) full?
Tekst from:
http://php.net/manual/en/mysqli.quickstart.prepared-statements.php