PHP MySQL 函数统计输出

Question

I wrote a function in which a value for a button should be fetched from two tables. Five buttons should be displayed side by side. This works theoretically, but the output is displayed 5 times for the first button, 4 times for the second button, etc.

What am I missing that the output is output multiple times?

function get_strat($map_id, $map_site, $operator_role_input) {

    global $connection;

    $query = "SELECT * FROM strat WHERE map_id = $map_id AND strat_role_id = $map_site";
    $select_all_defense_strats = mysqli_query($connection, $query);

    while($row = mysqli_fetch_assoc($select_all_defense_strats)) {

        $map_id = $row['map_id'];
        $operator_id = $row['operator_id'];
        $operator_role = $row['operator_role'];

        if($operator_role === $operator_role_input) {
            $query = "SELECT operator_name FROM operator WHERE operator_id = $operator_id";
            $get_operator_name = mysqli_query($connection, $query);

            $row = mysqli_fetch_assoc($get_operator_name);

            $operator_name = $row['operator_name'];

        } 

        echo $operator_name;

    }
}

<div class="btn-group">
    <button type="button" class="btn btn-default">
        <?php 
            $operator_role_input = '1';
            get_strat($map_id, $map_site, $operator_role_input);
        ?>
    </button>
    <button type="button" class="btn btn-default">
        <?php 
            $operator_role_input = '2';
            get_strat($map_id, $map_site, $operator_role_input);
                    ?>
    </button>
    .... (up to 5)

Answer 1

Because your variable $operator_name is outside of if statement . When it has value - it prints it. When comparing is false - then it's undefined .

Put default value of it before if statement :

$operator_name = '';
if(){...}
echo $operator_name;

Or just put your echo $operator_name; inside and in the end of your if statement .