Question

我正在使用以下查询，希望查询结果显示在单引号内，例如“ 10AM”。

$sql2 = mysqli_query($con, "SELECT concat('''', appointment_time ,''''), concat('''', appointment_end_time ,'''') FROM Appointments WHERE appointment_with LIKE 'Sarah'");

if (!$sql2) {
    die('Invalid query: ' . mysqli_error());
}

while ($row2 = mysqli_fetch_assoc($sql2)) {

    $time = array($row2['appointment_time']. "," ." " . $row2['appointment_end_time']);

    $appointment = [];

    foreach ($time as $appointment){
        echo $appointment;
    }

当我在phpmyadmin中运行代码但在我的php代码中运行代码时，此方法工作正常，因为我收到以下消息。

注意：未定义的索引：第140行/Applications/MAMP/htdocs/booking-system/index.php中的约会时间

通知：未定义的索引：/Applications/MAMP/htdocs/booking-system/index.php在第140行中的约会结束时间   ，

为什么会这样？

Answer 1

您需要在SQL中为字段指定别名...

$sql2 = mysqli_query($con, "SELECT concat('''', appointment_time ,'''') as appointment_time, 
            concat('''', appointment_end_time ,'''') as appointment_end_time 
        FROM Appointments 
        WHERE appointment_with LIKE 'Sarah'");

对于主循环，您似乎要构建一个数组以再次打印出来，可以将代码减少为...

while ($row2 = mysqli_fetch_assoc($sql2)) {
    echo $row2['appointment_time']. ", " . 
               $row2['appointment_end_time'];
}

MySQL查询可以在phpmyadmin中工作，但不能在php代码中工作，原因为何？

1 个答案: