Php: change value of variable based on dropdown
Learning PHP and a problem I can't figure out. I read that PHP only has capabilities for functions, so I'm not sure why my switch statement is not changing the value of the variables.
Purpose: Modify mysql SELECT statement based on user selection of dropdown.
the form:
<form action="contacts_show.php" method="POST">
<select name="grade" id="grade">
<option value="all">All Levels</option>
<option value="elementary">Elementary</option>
<option value="middle">Middle</option>
<option value="senior">Senior</option>
<input type="submit" name="browse" id="browse" value="Browse" />
</form>
PHP (edited to shorten the code):
$levelSelected = $_POST['grade'];
if ($levelSelected == "all") {
$querySelect = "SELECT * FROM teachers ORDER BY school ASC";
} else {
$querySelect = "SELECT * FROM teachers WHERE school LIKE %$levelSelected% ORDER BY school ASC";
}
$query = $querySelect;
$result = mysqli_query($connection, $query);
confirm_query($result);
confirm_query function if needed:
function confirm_query($result_set) {
if (!$result_set) {
die("Database query failed.");
}
}
When All Levels is selected from the dropdown list, the code works as expected. When any other option is selected, my confirm_quaery function states that the request is failing.
I'm not sure why the variable values are not toggling.
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To comment on my comment:
Change LIKE %elementary%
to => LIKE '%elementary%'
and do the same for the rest.
You need to wrap the pattern match in quotes and according to the guide:
mysql> SELECT 'David!' LIKE '% D% v%';
mysql> SELECT 10 LIKE '1%';
You also don't check for DB errors.
Add or die(mysqli_error($connection))
tomysqli_query()
If that still doesn't work, then it is also a scope issue.
Pass the connection to your function, make it not global.
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