如何获得单选按钮选择与数据从mySql

Use can set radio box checked as shown below
 if ($fetch['sex'] = 'male')
    {
    echo "<td><input type='radio' name='sex' value='male' id='sex' checked> Male <input type='radio' name='sex' value='female' id='sex'> Female </td>";
    }
    else
    {
    echo "<td><input type='radio' name='sex' value='male' id='sex'> Male <input type='radio' name='sex' value='female' id='sex' checked> Female </td>";
    }

所以我认为这应该行得通

$dummyAnswer = new stdClass();
$dummyAnswer->value = "somevalue";
$dummyAnswer->description = "some description";
$secondDummyAnswer = new stdClass();
$secondDummyAnswer->value = "second somevalue";
$secondDummyAnswer->description = "second some description";
// just a dummy, here would be your database result array
$arrAnswer = array(
    $dummyAnswer,
    $secondDummyAnswer
);
//wherever that comes from
$selectedValue = "somevalue";
foreach($arrAnswer as $index => $ans) {
    $checked = ( $ans->value == $selectedValue )? "checked" :"";
    echo '<input name = "answerswer_'.$index.'" type="radio"  value="'.$ans->value.'" '.$checked.'> '.$ans->description.'<br>';
}

这就是三元运算符派上用场的地方:

$checked = (statement here) ? 'checked' : '';

将(statement here)替换为布尔值(1或0)，例如$ans->field_name_here

然后将$checked放入您的<input>标签中，并确保输入的值为1:

<input name = "answerswer_'.$i.'" type="radio"  value="1" '.$checked.'> '.$ans->descript.'<br>