你理解错了sql和数据集的概念。$sql3="select taskid from jobrequest where status>1 and status <5";
$result3=mysql_query($sql3,$conn) or die(mysql_error());
//$sql2="select groupid from tasks where id in ('".$result3."')";
//$result2=mysql_query($sql2,$conn) or die(mysql_error());
$idstr;
while($row=mysql_fetch_row($result3))
{
$id=$row->taskid;
$idstr.=$id;
}...
$result3=mysql_query($sql3,$conn) or die(mysql_error());
//$sql2="select groupid from tasks where id in ('".$result3."')";
//$result2=mysql_query($sql2,$conn) or die(mysql_error());
$idstr;
while($row=mysql_fetch_row($result3))
{
$id=$row->taskid;
$idstr.=$id;
}...
$result3=mysql_query($sql3,$conn) or die(mysql_error());
$sql2="select groupid from tasks where id in ('".$result3."')";
$result2=mysql_query($sql2,$conn) or die(mysql_error()); $result3 是一个数据集合,而SQL的IN()里面的数据要求是数组
你做第二次查询先处理一下$sql3="select taskid from jobrequest where status>1 and status <5";
$result3=mysql_query($sql3,$conn) or die(mysql_error());
$result3=implode(',',$result3);
$sql2="select groupid from tasks where id in ('".$result3."')";
$result2=mysql_query($sql2,$conn) or die(mysql_error());
$result3=mysql_query($sql3,$conn) or die(mysql_error());
$result3=implode(',',$result3);
$sql2="select groupid from tasks where id in ('".$result3."')";
$result2=mysql_query($sql2,$conn) or die(mysql_error());