当我尝试运行此查询时
$SQL = " SELECT * FROM info WHERE username = '$led_nem'";
$result = mysql_query($SQL);
while ($db_field = mysql_fetch_assoc($result)) {
$tsk = $db_field['group_task'];
}
我收到这个错误
注意：未定义的变量：C:''examplep''htdocs''online''online中的led_nem任务管理系统''Task_mem.php，第71行
在使用变量$led_nem之前测试它是否存在：
if (isset($led_nem)) {
$SQL = " SELECT * FROM info WHERE username = '$led_nem'";
$result = mysql_query($SQL);
while ($db_field = mysql_fetch_assoc($result)) {
$tsk = $db_field['group_task'];
}
}
使用此
if (isset($led_nem)) {
$SQL = " SELECT * FROM info WHERE username = '".$led_nem."'";
$result = mysql_query($SQL);
while ($db_field = mysql_fetch_assoc($result)) {
$tsk = $db_field['group_task'];
}
}