Pass selected option value to mysql query - php

Question

I have an html select that is filled with data from the database.
It looks like this
echo '<select name="client_list">';
foreach ($htmlselect as $key => $row) {
echo
'<option value='.$row->CUSTOMERCODE.'>'
.$row->CUSTOMERNAME. '</option>';
}
echo '</select>';
Below it I have a table that is populated with values from the DB.
$table = $wpdb->get_results('SELECT STRING, DATE, STRING02 FROM `CUSTOMERFILE` WHERE `code` = 2 AND `status` = 2');
echo '<thead ><tr >';
foreach ($header as $list) {
echo '<th >' . $list . '</th>';
}
echo "<thead></tr>";
if ( !empty( $table) ) {
foreach ( $table as $key => $value ) {
echo '<tr >';
foreach ( $value as $a ) {
if (empty($a)) {
# code...
echo '<td>NULL</td>';
} else {
echo '<td>' . $a . '</td>';
}
}
echo '</tr>';
}
}
Now in this query I want to add to the where another condition that takes the selected option value from the html select
It would look something like this
$table = $wpdb->get_results('SELECT STRING, DATE, STRING02 FROM `CUSTOMERFILE` WHERE `code` = 2 AND `status` = 2 **AND STRING05 = selected option value**');
How do I pass the selected value in the query?

Answer 1

The $wpdb->get_results() function take 2 parameters, the first is the query and the second is the output
$wpdb->get_results($command, $output);