来自mysql查询的唯一数组

Question

Unfortunately I have one of those moments when my mind just feels frozen. Therefore I really need some hints on what am I doing wrong:

I'm getting multiple rows based on a category_id with:

$certificates= $DB->get_records('prog', array('category'=>$_POST['something']),'', $fields='*');

this returns:

Array
(
    [1] => stdClass Object
        (
            [id] => 1
            [category] => 1
            [sortorder] => 0
            [fullname] => First Aid Kit Certification
            [shortname] => CP101
            [idnumber] => 
            [summary] => 
            [endnote] => 
            [visible] => 1
            [availablefrom] => 0
            [availableuntil] => 0
            [available] => 1
            [timecreated] => 1561637136
            [timemodified] => 1561637944
            [usermodified] => 2
            [icon] => 
            [exceptionssent] => 0
            [audiencevisible] => 2
            [certifid] => 1
            [assignmentsdeferred] => 0
            [allowextensionrequests] => 1
        )

    [2] => stdClass Object
        (
            [id] => 2
            [category] => 1
            [sortorder] => 1
            [fullname] => Program fullname 101
            [shortname] => P101
            [idnumber] => 
            [summary] => 
            [endnote] => 
            [visible] => 1
            [availablefrom] => 0
            [availableuntil] => 0
            [available] => 1
            [timecreated] => 1561645727
            [timemodified] => 1561645727
            [usermodified] => 2
            [icon] => 
            [exceptionssent] => 0
            [audiencevisible] => 2
            [certifid] => 
            [assignmentsdeferred] => 0
            [allowextensionrequests] => 1
        )

    [3] => stdClass Object
        (
            [id] => 3
            [category] => 1
            [sortorder] => 2
            [fullname] => Certification program fullname 101
            [shortname] => CP101
            [idnumber] => S02
            [summary] => 
            [endnote] => 
            [visible] => 1
            [availablefrom] => 0
            [availableuntil] => 0
            [available] => 1
            [timecreated] => 1561707524
            [timemodified] => 1561707584
            [usermodified] => 2
            [icon] => 
            [exceptionssent] => 1
            [audiencevisible] => 2
            [certifid] => 2
            [assignmentsdeferred] => 0
            [allowextensionrequests] => 1
        )

)

Using this I get all the users that own this certificate with this(in a foreach):

$usrwcert = $DB->get_records('certif_completion', array('certifid' => $cert->certifid), '', $fields = '*');

and then I just do another foreach on this usrwcert and try and make a list of users with the results of it.

The thing is that each user has two certificates, therefore I get my users twice in the list and thats not something I want.

The print_r of usrwcert returns:

Array
(
    [2] => stdClass Object
        (
            [id] => 2
            [certifid] => 1
            [userid] => 2
            [certifpath] => 3
            [status] => 4
            [renewalstatus] => 0
            [timewindowopens] => 1590665879
            [timeexpires] => 1593344279
            [timecompleted] => 1561637992
            [timemodified] => 1561661794
        )

    [1] => stdClass Object
        (
            [id] => 1
            [certifid] => 1
            [userid] => 3
            [certifpath] => 2
            [status] => 3
            [renewalstatus] => 0
            [timewindowopens] => 1590666730
            [timeexpires] => 1593345130
            [timecompleted] => 1561665963
            [timemodified] => 1561709174
        )

)
Array
(
)
Array
(
    [3] => stdClass Object
        (
            [id] => 3
            [certifid] => 2
            [userid] => 2
            [certifpath] => 2
            [status] => 3
            [renewalstatus] => 0
            [timewindowopens] => 1590651581
            [timeexpires] => 1593329981
            [timecompleted] => 1561707581
            [timemodified] => 1561707582
        )

    [4] => stdClass Object
        (
            [id] => 4
            [certifid] => 2
            [userid] => 3
            [certifpath] => 2
            [status] => 3
            [renewalstatus] => 0
            [timewindowopens] => 1590651583
            [timeexpires] => 1593329983
            [timecompleted] => 1561707583
            [timemodified] => 1561707584
        )

)

How can I return only the unique fields in the last foreach? Here is my full code:

$certificates= $DB->get_records('prog', array('category'=>$_POST['something']),'', $fields='*');
foreach($certificates as $cert) {

            $usrwcert = $DB->get_records('certif_completion', array('certifid' => $cert->certifid), '', $fields = '*');

                foreach($usrwcert as $user){
                $userdet = $DB->get_record('user', array('id' => $user->userid), $fields = '*');
                 $mform->addElement('html', '<option value="'.$userdet->id.'">'.$userdet->firstname.' '.$userdet->lastname.' ('.$userdet->username.', '.$userdet->email.')</option>');

            }
        }

Thanks!

Answer 1

You can use the break to execute the last foreach only once, in this way you can avoid the next record for the same user

foreach($usrwcert as $user){
    $userdet = $DB->get_record('user', array('id' => $user->userid), $fields = '*');
    $mform->addElement('html', '<option value="'.$userdet->id.'">'.$userdet->firstname.' '.$userdet->lastname.' ('.$userdet->username.', '.$userdet->email.')</option>');
    break;
}