MySQL数据库中表单的默认选择值

Question

如何将以下选择字段默认为当前选定的rid？

<form method="GET" action="<?php echo $_SERVER['PHP_SELF'];?>">
<select name='rid'>
<?php
    $query= "SELECT * FROM resources ORDER BY resname";
    $result = mysql_query($query) or die(mysql_error());
    while($row = mysql_fetch_array( $result ))
    {
        $rid = $row['rid'];
        echo "<option value='".$rid."'>"
        .$row['resname']
        ."</option>\n";
    }
?>
</select>
<input type=submit>
</form>

这些代码非常丑陋，不要吝啬我。

Answer 1

我强烈建议您查看PDO或MYSQLi，因为从PHP 5.5.0开始，mysql_已弃用。

无论如何，我们可以使用ternary operator

快速完成

echo "<option value='".$rid."' ".((isset($_GET['rid']) && $_GET['rid'] == $rid) ? 'SELECTED' : '').">"

Answer 2

$query = "SELECT * FROM resources ORDER BY resname";
$result = mysqli_query($query);
while ($row = mysqli_fetch_array($result)) {
echo "<option value='" . $row['rid'] . "'"; 
if (isset($_POST['rid']) && $_POST['rid'] == $row['rid']) {
    echo ' selected="selected"';
}
echo ">" . $row['resname'] . "</option>";
}

Answer 3

$query = "SELECT * FROM resources ORDER BY resname";
$result = mysqli_query($query);
while ($row = mysqli_fetch_array($result)) {
    echo "<option value='" . $row['rid'] . "'"; 
    if (isset($_GET['rid']) && $_GET['rid'] == $row['rid']) {
        echo ' selected="selected"';
    }
    echo ">" . $row['resname'] . "</option>\n";
}